The new issue of UK's Mojo magazine has a few bits about Brian's current recordings. Details are still sketchy, but we do know Brian is recording, he is recording stuff presumably as "solo" material, Jeff Beck indeed was involved in actual recording for Brian's album, and Joe Thomas is still involved.
From the Mojo issue (via the Smiley Smile Board: http://smileysmile.net/board/index.php/topic,15536.425.html):
Earlier this year Wilson and Beck spent a week in the studio. "They got along famously and came up with some new things" says Brian's collaborator Joe Thomas. The LP's one non original, he added, is a traditional song familiar to them both from their youths.: " It's actually the first song Brian ever learned to sing from his grandmother," says Thomas. "Jeff Beck blasted off this one version and it knocked Brian out of the ballpark and then Brian came up with an arrangement and within a few hours there was this magical version" The song, whose title they're keeping secret for now " will blow everyone's minds".
Thomas reminded him of their 80 hours of unreleased material from those (1998) sessions. He put them in digital files and Brian referred to some when writing songs for last year's TWGMTR. Others he wanted to save for a solo record. "He was very specific about which were which," says Thomas, " and in a lot of cases, the ones for his own album are a lot edgier." He also wanted to write new songs. "I've known him for 20 years and I've never seen him so prolific." So many, Brian says, he can't remember the titles. There's "no concept" this time, "just music. I love the music."