is this a possiblilty like the older models to change background AND idle screens for any of the current BB's?

As far as I know, the idle screen is part of the theme. If you create a theme using Plazmic Theme builder, you can change this. Anyone else know if this is true, as I would like to change my idle screen as well w/out creating a new theme?

I use Plazmic's Theme Builder and there is no option to change or do anything with the Idle screen.

No not at this time