After installing the new AVR-Studio 4.14 I realized a new icon (the blue one in center). It links to a FLexible In-system Programmer named FLIP. Looks interesting - ends up in middle of the 8051 section of Atmels Web. There is a host part for a bootloader for 8051 as well as some At Megas (CAN, USB) but not for the ordinary ones - but mentions a RS232 IF too.
Has anyone played with this? Any more details on the bootloader required for the AVR side?