There's another SD/MMC stack for FreeBSD that's been posted. It was written by Akihiko GOTANDA-san using the SD simplified specifications. It works well for the Ricoh based parts, but fails to attach to my TI based parts. It doesn't have the hacks necessary to put the TI parts into standards conforming mode either, but even with those added there are some problems. This driver was recently announced in the mobile@ mailing list.
This joins my SD/MMC stack that I wrote for the Atmel AT91RM9200 port. Andrea Bittau also has written a 'sdh' driver that plugs into my stack. It works with Ricoh parts, but not TI parts either, but it gets closer than Gotanda-san's driver. It was announced a while ago in the mobile@ mailing list.
And there was much interest in my SD/MMC card talk at BSDcan! I'm glad to see more interest here.