Regarding the hardware of N9,Nokia can upgrade the hardware if they want because according to those who worked on hardware adaption of MeeGo they already covered TI chipsets.So it is possible to use TI OMAP 4xxx series processors if Nokia wants.But I think Nokia management probably prefers WP7 to have more glorious hardware.
Better hardware is always a welcome but as you say solid build OS is more important.
It think 1080p should be video standard for the time being(2-3 years).So as long as N9 can play 1080p videos it should be fine.Anyway I think further enhancement to the video playback is always possible.
Like N900 we can only play 320p video resolution but there is freemangordon's 720p video patch in kernel-power now.It still needs DSP codec but it's a good attempt to see whether N900 can 720p videos or not.Too bad we cannot use TI's Android DSP patch to be used in Maemo (it's not redistributable)

There is a talk that MeeGo Harmattan's swipe UI might be used in Symbian Belle.The UI alone won't make Symbian as good as MeeGo because being a linux OS MeeGo is much more capable OS than Symbian.

If Nokia Malaysia wants to talk about low sale of N900 in Malaysia I say they should blame themselves.How many of you ever seen N900 advertisment? How many of you seen N900 is (Ori set) in any phone shop?
There was lack of any kind of promotion for N900 in Malaysia.They might argue that N900 was released for specific kind of users only for me no matter kind of users it'll be you still need a good promotion.
I love the N900 release in India.It was some kind of linux festival

N9 have a lot of strong point that'll suit both advanced & regular users but the uncertainly over software support & developers support might make potential users to to think twice before buying the device.
I'm a N900 owner & long loved Maemo device but even I still thinking whether I should get N9 or not.

True, when it was announce, I was searching up and down, and very disappointed to find out that there's no plans to be launch in APAC region. Someone email Nokia Europe and the final response was there was no plans to be launch in APAC. The India people was very disappointed as there's many linux geek, HK as well, so many request and so on. In early days, AP companies didn't bring in ths device, have to buy online or from people who imported it, some people were selling in LYN for more than RM3K (if I'm not wrong). I bought it immediately when the AP companies bring it in, get it direct from the AP Company. Really hard to get this phone that time, but very satisfying feeling when you got it and hands on, there was real device to test or even look; Only source is YouTube, many interesting/attractive video showcase in-depth reviews and features of the phone; The best is the unboxing, watching how the device first boot up, it's amazing, unique, totally different from the rest; Watching it really poisoning.

To market the N9, Nokia really need a good advertisement that truly showcase it's uniqueness, something that attracts people, when they want it, they will want to try it/check it out at Nokia Store (if not made up their mind to buy it without hands on). Honestly speaking, Nokia doesn't really have good advertisements or advertisement that truly showcase the device; Look at N900 "transformers" ads,... it's useless, it's "entertaining" to watch, but shows nothing about the device really; On the other hand, take a look at Apple iPhone ads, it showcase the smoothness and simplicity of the OS, attractive UI, etc. People who watch it will "WOW", I want one (or at least check it out), or look at their phone... they will compare and think about iOS smoothness and/or simplicity.

Btw, the N900 launching in Malaysia seems nothing interesting. I'm not sure, I didn't see anything great, but take a look at India and HK launching, it was amazing. There's one Linux Mag from India, there's 9 pages of in-depth review of the N900, and in the last page, it mentioned, it didn't even cover half of the device, but he have to stop there due to page limitation.

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Added on July 16, 2011, 10:46 pm

I think for now, it's impossible for upgrade as they might already produce the device? Maybe IF they plan to launch a N9i, hahaha. 
But I would prefer a N900i 
Seriously, I still prefer Maemo OS, but it's limited by the hardware, and also the full source code of the OS to the community; That'll be crazy, but bad for business 

N900 "official" advertisement is... not interesting or truly show the device capability. As I mentioned in my previous post, they need ads that truly show the device uniqueness, etc. I think most of us also rather watch videos posted by reviewers or owners, it's far more interesting and makes you want to get one or touch one. Nokia needs this kind of advertisement, not those advertisement which doesn't really showcase anything useful about the device.

Initially, if I'm not wrong, there was promotion and ads, and also pushing on N900 when it was first launch; Nokia Shop have demo units, and ads, but most people don't know about it and the WORST PART, the sales-person knows nuts about it; This is where the biggest failure comes in, the sales person might only know about Symbian (actually, they might also not familiar with Symbian in depth despite they have the glorious chance to play it it everyday; like a car salesmen who have the opportunity to try the car, but they don't understand the car or in-depth on the car, imagine they have to refer to brochure and explains to customer? What's the point?).
Next, there's no proper support in their Nokia Shop, people who come for help, seems those people can't help them? E.G. USSD? Nokia Malaysia should help them pre-install some useful apps and also give some basic "traning" or "guidance" to those users how they can use the device and so on, but there's none. People who get this are helpless, unless they join the forum and get to know more about it finally utilizing it.