So the Britney and Iggy collaboration is called "Pretty Girls", and its allegedly out on May 5th!!
According to Iggy herself, she will be co-directing the music video, and the song will be on Britney's next album. Larry said in Billboard magazine that an album wasn't ready and that they were planning on releasing a few stand alone singles throughout the year while Britney takes her time to work on the album at her own pace, but some people are suggesting that they are just trying to throw people off the scent, and are actually planning to spring an album on us as early as June!
Theres still no news on the Giorgio Moroder track, the album was scheduled to be released on May 25th, but its now been pushed back.
EDIT: Looks like she is filming the video for Pretty Girls today!