Looks like they changed their license from LGPL to zlib as well. I wonder if this will increase adoption, or if it just was so Valve could use it in Steam for Linux.
I doubt it would be a huge issue for Valve; they already use LGPL code. However, it's often a big deal for small developers; simpler licenses mean simpler due diligence on investment and such, and a lot of companies are cautious of LGPL in anything that they'll be distributing.
While the FSF discourages use of the Android marketplace, they do say there's no specific GPL conflict. Compliance is potentially a bit more of a pain for the developer, of course; strictly speaking they have to make sure the LGPL-covered code is available for download for three years after distribution ends. They also strictly speaking have to provide a mechanism to re-assemble the app; example here: http://sparrowmailapp.com/lgpl.php (though note that a lot of people just don't bother).
