The wikipedia page says that it dates from the 90ies and is modeled after the PDP11. Main differences to AVRs seem to be that they are designed for lower power

The wikipedia page says that it dates from the 90ies and is modeled after the PDP11. Main differences to AVRs seem to be that they are designed for lower power consumption and are von Neumann instead of Harvard architecture, otherwise it depends on your requirements which processeor fits your needs. For example, the lager controller included in this bundle compares to the Attiny 2312, which has the same amount of RAM and ROM, the same 16MHz maximum clock, more IO-pins, another timer, PWM-channels, some EERPOM and a hardware UART, but higher power consumption and fewer and slower ADCs. As to why now, I think they are targeting the educational market (there is a special link for universities on the wiki page), trying to get exposure to students who would otherwise default to using arduinos for term projects. They are not selling these boards for profit, but for mindshare.