The way I see it, Alien Hominid HD has set a precedent. It's living proof that independent games developers can get ahead with Microsoft. While the game has been around since its Flash game prototype in 2002, the original console release in 2005 was virtually impossible to acquire in stores (I certainly didn't spot one) and this re-release on XBLA gives it the potential to reach a very significant audience, many of whom are more than likely prepared to drop 800 Microsoft points for it.
This ties in well with XBLA itself; it really needs more indie games. Josh over at Cathode Tan has an article up about what the XNA competition might mean for developers, and that's well worth a read, but this should also affect gamers. People are going on the record stating how digital distribution is becoming the only real way for independent developers and Microsoft should really be listening to this. Seriously listening, not just running a little competition for good PR.
Microsoft have people eating out of their hands right now when it comes to XBLA: a mere mention of the notion of porting some classic game over (no matter how much of an April Fools it's likely to turn out to be) is enough to satiate our lust for speculation. Clever independent games would be a godsend, certainly beating seemingly endless reams of arguably lousy retro titles, hastily updated with HD graphics. The mistake Microsoft are making with the XNA competition is saying how only one game will get released on XBLA. They should be more accommodating: it should be many games.
Imagine a year where something unique is released every other week. It would be incredible. Alien Hominid is a start, but it's an update of a game that's already been released twice. Original, new, independent games would be a great way forward. Quality isn't exactly an issue: if people are prepared to pay for Time Pilot and Root Beer Tapper they're probably willing to buy whatever Microsoft decide to sell. It would turn XBLA into a varied, interesting distribution platform instead of a retro dumping ground with the occasional decent title.
I'm sure that if there are sufficient quality titles, then the other good ones won't have any problem getting publishers. EA and Vivendi (as Shin Sierra Online) have made no secret of their desire to bring lots of games to the space.
The interesting question will be how many of these indie developers will stay indie in the face of such wanton title lust from publishers. Wanako recently sold out, and it's probably just a question of time for others.
The Behemoths, Gastronauts, and Ninja Bees of the small games industry are making their marks though, and building a reputation for quality.
Hey look, a Sundance festival for game devvers!
Note how homebrewers made it onto the gba version of the Activision Anthology. Another (better?) example might be gba Yars' Revenge which, iirc, was originally a labor of indie love.
There is certainly a market for single-developer or low-budget developers... oxymoronically attested to at least in gameplay by Warioware. As gaming co's jump into big budget productions, a void for The Blair Witch should open a bit wider.
Good games are good games. As you (Martin) point out, it's about exposure. Getting away from brick and mortar shelf space (nicely mixed image there) is a good move for indies.
Now if we can get LimeGameWire installed on the Xbox, we'll be getting somewhere.