Err... shouldn't you have waited for the upcoming one? Its just right right at the corner...

To reply your questions:

1. Is it better to upgrade to the OS3.0 or not? Coz I see some ppl wanting to downgrade back to 2.2.1 as well.
This is entirely up to your preferences. iPhone OS v3.0 introduces a lot of new features not found on previous revisions. However, you can put it in
such a way that the new revisions taxes your hardware more. 3.0 is still new and bugs are natural. I would expect 3.01 whatever to come out soon,
probably in weeks. You should update, to be honest.

2. Why do some of you say the upgrade CD from Maxis is useless?
The CD is useless because you can get the same update from iTunes 8.2 and you can get it earlier than waiting for the postage to come, around 2
days late. However not many users are as tech savvy or may not know they can get the update from iTunes. So the CD will help them.

3. If don't upgrade via the CD, how else can we upgrade to OS3.0?
iTunes 8.2 and a stable internet connection.

4. Since my unit is jailbroken, will there be any problems if I upgrade?
A lot of JB-utilities has been released in the last few days. You should check it out for any limitations on any of them.

This post has been edited by davidmak: Jun 23 2009, 09:46 PM

I am waiting for the information too. I was planning to get a new compact camera to supplement my DSLR. But if the price is right, I may skip it and get 3G[S] since my wifey wants an iPhone 3G too.

Bro, try out this USD$0.99 app called Free Memory. It doesn't requires any jailbreaking and is available publicly over at App Store. Just use the search tool and look for Free Memory. You'll be shocked to see that the average remaining RAM around 3-4MB! Thats why everything is so slow. Click the free memory button and it'll free up to 20MB of RAM sufficient for most programs. Give it a try.