Apple Increases iPhone App Download Over 3G to 20MB: Is AT&T 3G Tethering Coming Soon?

According to AppAdvice.com…

Apple Pushes The App Over 3G Download Limit To 20MB, Prepares For The iPad?

Previously, the app size download limit over 3G (but not WiFi) was 10MB. AppAdvice speculates that this app file size increase is preparation for the iPad 3G model launch in April (the WiFi-only model launches next week). This sounds like a perfectly reasonable guess to me. However, there are other interesting changes like allowing VoIP (making voice calls over the data network) over 3G in the past couple of weeks.

Apple gave AT&T its seal of approval last month when they announced that the iPad 3G model’s mobile carrier data service would be provided by AT&T. Could it be that AT&T is getting its 3G data network act together? Does this mean they will finally make 3G tethering available to iPhone users?