Nobody posted here for awhile, but i have a new (pretty much a) success to add.
I am using an unlocked HTC / AT&T 8525 With Windows Mobile 5.0 with a Toshiba 8GB MicroSD Class 4 memory card.
Installed the .CAB, reboot. Reads the card fine but only at 4GB capacity (So it shows approx 3,500 MB free). Better than the 2GB I had before, but I guess maybe Win Mobile 5 will only read a 4GB card. Going to update to Windows Mobile 6 or 6.5 very soon so perhaps I will update if I remember.
I previously used a 2GB MicroSD card that was full to capacity. I had almost all my software intalled on the 2GB card, which I copied to PC, then back to the 8GB card. Turned off mobile device, inserted 8GB card, booted mobile device, all software there and working fine.
The only drawback other than using 4 of the 8GB on the card is that it removed my Xpress Mail e-mail entirely, which wasn't a big deal for me since I use Gmail and all of my e-mail is saved on server and online. I re-registered no problems whatsoever. E-mail back on phone & working fine. Wireless, bluetooth, etc. all working fine. But if you download e-mail to your phone and do not have copies saved on server you should back it up before doing this on this model phone at least I would recommend. Will update later if I am ever able to get the full 8GB capacity on this phone.
Good luck to all!!