Medium-sized answer - maybe later.

Long answer - 

I've talked to both an advocate at Google and a couple of Samsung reps about this issue. Basically, the problem is that the Android platform itself doesn't have a means to do video output, per se. So, when you do get things like the Droid X and Galaxy doing HDMI out, that's via implementations written by Motorola and Samsung. They then provide that mechanism to their own apps, but they're private. In fact, I'm surprised that Real HDMI app works - that's interesting. 

It'd take two more steps to get widespread access to this elsewhere. First, it'd be most likely that Google would initially do a simple wrapper around vendor-specific implementations. Then, past that, they'd need to do a standard platform implementation.

Now, there is this little thing called Google TV, which will need HDMI out by default. My strong suspicion is that output will get rolled into the Android SDK in early 2011 when the Google TV SDK comes out. Of course, there's no guarantee that Android (the mobile SDK) and Google TV will get this feature at the same time, or that all devices will support it. And it's even less certain that a device you buy now will support that version of Android.

Not to be bleak, but until you see official support, I wouldn't be too hopeful. Now, when it does happen, though, a $300 Google TV could wind up being a killer performance / installation machine.