Well that is the case for now anyways.
In case you have been living with your head under a technological rock AT&T is planning on buying T-Mobile. Should the fates allow this to happen (here is to hoping antitrust acts prevent it from happening) AT&T as announced they are planning on taking down T-Mobile's 3g/4g/HSPA+/WhateverYouCall it network due to "upkeep" costs. Never mind the fact that T-Mobile's network blows LTE out of the water - the fact that this network will be going offline means the N900's mobiles speeds will be rendered relatively useless in the Unite States (AT&T's network only gets about 15kb/sec with the N900's radio). Not to mention even if the N900 did get decent speeds on AT&T's network their mobile internet plans are horridly restricted (and priced even worse)!
Now not just the N900 will loose its mobile internet snappyness if this merger happens - all TMO handsets will. AT&T's solution? Get everyone phone upgrades (They factored this cost into their merger). Its a shame that this leaves all of us that purchased our handsets outright (such as the N900) out in the cold, reminds me of the many reasons I left AT&T some time ago. Honestly though, even if they where going to offer everyone a free handset - nothing on the market currently can really measure up to what Maemo does. I had been hoping to get a few good years out of my N900 as it does everything I could ask from a handset and I just recently purchased a second N900 for my girlfriend to use, guess I should have waited on that decision.
If the merger does go through the best I can hope for is a decent handset from the Samsung Linux Platform some time in the next year to replace Nokia before my mobile internet drys up. Anyone else hoping this merger falls through?