@mattconfusion: good on you for trying out the latest code :) - in fact thats the code I'm currently working on ... only made that branch a few days ago haha. As long as you're prepared to face bleeding-edge issues, by all means go ahead and keep testing it. Please let me know of any issues, but make sure you update the code before reporting, in case it has actually been fixed. Also, some things are knowingly broken...see the ChangeLog file.
FYI: the db_cart branch work is intended for the eCommerce 1.0 release. I've got rid of all the session-based cart stuff and now carts are stored straight to the database.
We're planning to release v0.7 very soon as a proper stable release. That will come from a combination of the branches: trunk, burnbright & sunnysideup.