While upload speeds (HSUPA) are typically not as important to smartphone users, AT&T has stated that they expect to have all of their 3G coverage areas upgraded to the faster HSUPA standard by the end of June. Perhaps just in time for the 3G iPhone release? This upgrade would bump user's upload speeds to as much as 2 megabits - at least in theory. AT&T says they predict typical end user speeds to be in the vicinity of 800 Kbits.
Not all devices that support HSDPA (the download spec) also support the HSUPA spec, so check your potential device's specs to be sure. Palm does have support for HSDPA on it's WM6 devices (like the Treo 750), so the upcoming 800 series should be poised in that area as well. We haven't seen formal mention of Palm supporting HSUPA, but hopefully it will be included in the upcoming devices.
You may ask then, why the hype over improved upload speeds? It could be related to the rumors about the new 3G iPhone having video calling capability. If true, and the iPhone has the rumored front facing camera, it could require that additional speed for uploading the video. Shouldn't be too long until we know the facts on that. I've always thought a break through service would be video calling via a smartphone, but in order to make that work, you need fast upload speeds. Could be pretty sweet. Palm - are you listening?
AT&T has also stated that they plan on having nearly 350 markets on their 3G service by the end of the year. Currently AT&T has around 275 such areas, so that's a nice improvement. I know some folks have really been waiting for that expansion. In particular, both Mike Overbo via the TreoCentral TreoCast, and Jennifer Chappell have been wishing/praying for 3G coverage. Sadly, AT&T has not stated exactly where these additional markets will be.
Time will tell whether AT&T can deliver on all of the promises of improved upload, download and 3G coverage area expansion, but based on statements they've made, 2008 looks to be a promising year for AT&T smartphone user's online experience.