The HTC Aria looked like it was going to get the HTC sync app as it appeared on their website recently. However, the app has now been removed which now would prevent non-android market applications from being installed on the device.
When the app first appeared on HTC, people were thinking that AT&T [T] were relaxing the rules a little and letting 3rd party apps be installed on the handsets it offers as a carrier. However, now that the side-loading app has been removed this is not the case.
It’s a shame really as many would like the ability to install apps this way, and now it isn’t possible using this method. What made it look like it was a mistake in the first place is that AT&T had not pushed out a firmware update to utilise the side-loading sync system.