The State of Android

Jean-Baptiste Queru had this to say upon the release of the Froyo code into the Android Open Source Project (the "dump" of Froyo, making it available to modders, coders, reviewers, bug hunters, etc.):

In order to make it easier for device manufacturers and custom system builders to use Froyo, we’ve restructured our source tree to better separate closed-source modules from open-source ones. [...] We’ve also incorporated into the core platform all the configuration files necessary to build the source code of Android Open-Source Project on its own. You can now build and boot a fully open-source system image out of the box, for the emulator, as well as for Dream (ADP1), Sapphire (ADP2), and Passion (Nexus One).

Very interesting. That's a big portion of the Android phone market that's going to be upgradable to Froyo very easily. Google are paying attention to fragmentation. But here's a rundown anyway:

The Good Stuff

Have a Droid, Dream (G1), or Magic (G2)? Don't wait for CM6, upgrade now. It may not be OTA, but it's worth it, and it's easy to install.
Have a Slide, or Hero? CM6 is just around the corner: it looks to be a pretty snappy release. Follow @koush for updates.
Have a Desire or Evo? Get CM6 if you want, but your OTA should be arriving shortly (or a few days ago :-).

The bad Stuff

Have a XPERIA™ X10_(lulz)? Just wait; the modders should catch up with you in a bit. Alternatively, you've only got the rest of the year to wait until you get 2.1. No word on what's after that, though. You better hope these latest configuration changes Google have done make it easy for Sony. Otherwise you'll end up like...
Telecom's new Android phone: the LG GW620f. Well, you're screwed. 1.5 or 1.6 for you, and no upgrade in the forseeable future. No eclair, no froyo, no gingerbread. No WebM, no native Exchange support (instead supported by potentially crappy third-party app), no Google Navigation, no Swype, no ADW launcher, no multiple Google profiles, no Twitter and Facebook contact syncing, no Google Apps support, etc. And you'll miss out on this:

On the performance front in particular, we have seen realistic improvements of 2x to 5x for CPU-bound code, compared to the previous version of the Dalvik VM. This is equivalent to about 4x to 10x faster than a more traditional interpreter implementation. (Dan Bornstein)

Really: if you want to get a reasonable Android experience, buy a phone with an unlocked bootloader and a recent version of the OS. The improvement from 1.5 to 2.2 is huge.

Ultimately, I think, consumers will just have to factor this into their decision of which brand they purchase. HTC has generally very upgradable phones: it treats Android well. Google marked phones (Dream, Sapphire, Nexus) do also. Others vary. Buy accordingly.