I had the same problem and have massive trouble believing that there are not enough playlists for some of these albums. For me the latest album to work is Swim, by Caribou (released 19 April 2010). Nothing released after April 2010 is working for me with genius.
I get the "Genius is unavailable for the song ..." message for all the following (all bought in iTunes - sometimes whole album, others just a few songs):
The National - High Velvet - released 10 May 2010
The Black Keys - Brothers - 17 May 2010
Dark Night of the Soul - Dangermouse and Sparklehorse - 9 July 2010
Arcade Fire - The Suburbs - 2 August 2010
Maximum Balloon - Maximum Balloon - 10 September 2010
Edwyn Collins - Losing Sleep - 20 September 2010
Mark Ronson & The Business International - Record Collection - 24 September 2010
Belle and Sebastian - Write About Love (Bonus Track Version) - 8 October 2010
Warpaint - The Fool - 22 October 2010
Take That - Progress - 15 November 2010
Lady GaGa - Born This Way (Single) - 11 February 2011
Before that, even obscure albums (eg The Ruby Suns, Fight Softly (1 March 2010)) work fine. Strangely, genius used to make a playlist for me with the song Bloodbuzz Ohio,
by The National, which I downloaded from the band's website shortly after release (24 March 2010). But after I bought the whole album High Violet, both the single and the album stopped working.
I called Apple Support about it and got escalated one step up the chain. The guy explained that genius works on a combination of local and global information, local being information from my computer, and it needs local information before it can make a playlist. I asked him if that meant that genius could work for someone else, but not for me, on the same song, and he said yes. He said I need to just keep playing the songs and updating genius. Well I bought the Arcade Fire and The National shortly after release and have played them close to 40 times each, and have now even made special playlists to try to train my iTunes to know what I think goes with these songs. I just can't believe there's not enough local or global information to make a genius playlist with these songs. It doesn't explain why a song used to work but no longer does. Plus the suggestion that I need local data before genius will work is not correct. I just bought Jailbird by Primal Scream (a 1994 release) and before playing it I updated genius. It then created a genius playlist just fine, despite it never having been played locally.
Genius has been a big reason I've bought off iTunes rather than going for some kind of subscription service, but I've been waiting for updates for such a long time now and it seems like some bug has frozen it for all songs over about the last year, or Apple has just stopped bothering to update it. It is frustrating getting unconvincing answers from Apple Support. If anyone has any of these working, or gets any decent information from Apple Support, please post here.
MacBook Pro 13 inch Oct 2009, iTunes 10.2.1(1), Mac OSX 10.6.7
