I've only seen videos of it on the Rhyme and from that it looked like a stripped down version of 3.0, so I didn't know if it was going to go "mainstream" or not. However there was that mention that Sense 3.5 has some special Dropbox integration with an extra 3GB of storage (on top of the standard 2GB) so maybe there will be a general release/upgrade of 3.5 to Sense phones.