The speeds will be higher than 300 in almost every area, in my opinion, but like dturner said, there will be a great variation in speeds between said areas. City areas will of course get better reception of signal, and thereforee better speeds.
I wouldn't count on a consistent 600-800 range, but it could happen. Good luck.
I don't think they will be capped at all. Unfortunately, (and this is just my guess only), I think most people will find their speeds limited to the 300-400kbps range just due to the limits of the 3G network right now. Some may see over 500, but I kinda doubt it will be the norm.
I think, of the people reporting here, we will see more complaining about <300k speeds than those gloating about >500k.
Word was they were capping the speed for the iPhone because of the heavy traffic.
Its not that Jobs is oblivious to the fact that his 300somethingkbps speed he got on the 3G is extraordinarily slow for 3G.....he was emphasizing it was double Edges speed....fooling the ignorant that that's a great thing, but also preparing the knowledgeable for a capped 3G experience.
I'm on the web by necessity all day long, and that wont be acceptable . I'll continue with the tilt (which IS consistently at 700ish here in Chicago) when needed, but probably get this new Samsung Omnia
In well-covered areas, EDGE should be 200+. According to Apple's web site, in well-covered 3G areas we should see 2-3x speed improvement. This would put it around 400-600 on average. If there is no throttling, I'm going to guess that burst would be 800+, such as for downloading songs, apps, attachments, etc.