Ok, so it's been several years now that Palm has supported SD cards, yet, many major SW apps still don't support them.

For example, two of the biggest RAM hogs (the databases, not the apps) that I use are SnapperMail and Wine Enthusiast.

Now, I am not complaining about the size of the databases... SnapperMail's DB size is directly relational to the preferences a user sets and the amount of mail/attachments they store. With Wine Enthusiast, it is what it is ... lots of data.

Is there an OS or HW issue that is holding back this natural progression of storing thin apps in the internal RAM and their respective fat databases on external SD cards?

I have 2 nice big 512MD SD cards for my Treo 600 that aren't really being used as much as I'd like! For instance: to store application databases and not the apps themselves!!