I'm really looking forward to the release, as I'm going to get some sort of next gen phone when I upgrade later in the year (either this one, or the iPhone). I thought the iPhone was a bit gimmicky (but good fun) when it came out last year, but now that some really good 3rd party apps are out, it will be a really useful tool when I'm out and about
The G1 does have some shortcomings though, such as the lack of multi-touch, headphone jack and a camera flash (which most camera phones have nowadays). I've got higher hopes for the ones coming out in 2009 though
Shouldn't be too long until T-Mobile stores have some in stock to play with