AT&T's network sucked before the iPhone...and the iphone is just making it worse.
http://www.nytimes.com/2009/09/03/technology/companies/03att.html?emc=eta1
If Verizon had to deal with the amount of data traffic that AT&T does, you'd have the same connectivity issues. Lucky for Verizon that no one uses much internet service on the Blackberry because the user experience sucks.
The real problem is not AT&T, it's AMERICA. Japan, Korea and most of Europe have FAR, FAR better/faster cellular data service, but the USA is sadly lagging WAY behind.
I hear its finally getting MMS. Officially. Thats pretty crazy that its been out for 2+ years and has never been able to send picture messages...
It goes to show how awesome the other features are to make everybody forget it cant do MMS..