Huh? Just sharing my point of view only, everyone has theirs.

Personally, I don't really like WP7, but I gotta admit that the OS is smooth and it's stable. People like smooth and stable OS, if WP7 can deliver it, I believe Nokia users will like it, especially current Symbian OS user; Many of them switch because of the OS issue right? The instability, problems, etc. although the latest Belle kind of changes things again, brings back excitement and it's much smoother and nicer to use.

As I know, previously MeeGo was meant to be in top of the line Nokia device, their high end device; It's said to be a class above typical smartphone OS. Sadly, the vision didn't come true.
For current MeeGo, it's nice but still lacking in functions and features on the OS, still have many things to refine and add. The Web Browser is like at it's basic version, very plain, no settings, no bookmarks, no history, etc. It's like they rush to deliver the product, so they deliver it a basic running version, the OS seems so too; So, personally, I think it'll need more updates for it to be a really good OS (it's the same case when N900 was introduced, the Maemo OS was also like a rush product to deliver, and it's very "incomplete").
I suppose WP7 also same, they provide a simple, smooth and very stable OS, then slowly adding more functions and features, and refinements. Will MeeGo get the same treatment? I hope so, but the thing is, there's no future MeeGo device from Nokia? Wonder how will it justify on this.

For current N9, still, the specs, people are still concern with specifications; Next year, the current spec of N9 will fall behind even further. Can't deny this fact, and how people will see it.

Lastly, one of the important part, as everyone already knows, applications and games; particularly those in demand and popular, e.g. WhatsApp; Not having this app alone, is enough to deter quite a lot of potential customer. I think it's a big disadvantage to Nokia, they should've work this out as they may have been able to capture more potential customers.
What do you think? Imagine if the application is available, how many people previously given up would've gone for the device...