I'll echo what other 7D owners are saying. I love this camera and have absolutely no regrets. It is impossible to predict when any camera will be updated, but from what I can tell from this site and others, there is no reason to believe a 7D upgrade will come any time soon.
Right now, the 7D is selling in the U.S. at an all-time low (below $1,500), so it's a good time to buy. Price drops seem to be incremental and marginal, so I doubt if you will save big bucks waiting and you may actually see a price increase.
Canon has been careful not to cannibalize the major features of the 7D and the things that count (resolution, auto-focus, frames per second, etc.) are still at the top of the line on the 7D.
One thing that I think is very telling: On this and other forums, you'll almost never find comments from disappointed 7D owners. I haven't seen any ratings, but I suspect that it has an extremely high rate of customer satisfaction.
You mentioned the 430 EXII. Because the 7D has a built-in infrared trigger, you can buy the 430 EXII and use it off-camera as a slave or remote if you want.
Someone else on the forum put in a pitch for the 17-55 f2.8 EF-S lens. I will also recommend the 15-85 mm EF-S lens.
It's a matter of personal preference, and comes down to which is more important to you: the constant f2.8 aperture of the 17-55 or the wider range of the 15-85mm. I came down on the side of the versatility of the wider range. Others want the speed. I use other lenses when speed is the deciding factor. The fact is, I dutifully fill my bag full of lenses and then find at the end of the day that I've used this lens for almost everything.
Just a few thoughts. Main one though is: Buy the 7D. You won't regret it.