Xbox Live Gamertag API Acess
It would be really cool if developers could get api access to Xbox Live Gamertags, that way they don't have to make users create a new account just to play multiplayer games. It would also help a lot for leaderboards too.
Just open the xbox API to indie developpers. It would help create an ecosystem around xbox and would be a really nice selling point to Windows phone!
RP Interactive commented
This idea is the same as "Open access for XBOX Live achievements", so those votes may add up here too. I will tell it here too, that it may be ok if the Xbox team wants out of this, but having no concept about an achievement system is like asking the gamers to spend their money on other platforms. I'd like to hear a Microsoft Phone employee having all our concerns answered.
Simon Felix commented
Access to avatar images would be helpful too.