No, it doesn’t have 4G connectivity. It has HSDPA, which as they describe uses one antenna to send data, one to receive (Think DC vs. AC current), so it’ll be double the data speed it was. It’s not the same as 4G which Verizon, Sprint, and AT&T have along with almost all new Droid phones.
Differences from your 3GS:
Will it be an upgrade from the 3GS? Yes, very much so.
Will it be possible to upgrade the 3GS to IOS 5 when it comes out? When IOS 4 came out didn’t they limit it to the two newest phones thereby kinda forcing the 3G owners to upgrade?