Er... to be honest, nothing really comes to mind. I just scrolled down AS's entire list of series and didn't encounter anything I'd label "shounen-ai." A few months ago, Kyou Kara Maou would have been my first recommendation--it's funny as balls--but it got licensed. The Mirage of Blaze OVA is currently out (albeit unsubbed), but you definitely shouldn't watch it without first seeing the licensed and fully released TV series.
So I'd advise you to wait a little while; there are a surprisingly large number of shounen-ai OVAs and TV series coming out in the not-so-distant future. Meine Liebe is obviously the first (although I have yet to see any concrete evidence that it will be shounen-ai or at least shounen-ai-ish), and if nothing else it'll be graced with Bee Train's spectacular production values. One or two others have been mentioned on these boards, including a Loveless OVA (points to avatar), which will hopefully improve on the so-so manga.
While shoujo-ai is really in vogue right now, chances are that things will have begun to balance out by the first half of 2005.
