So at the moment we have:

• Jolla announced that CPU was selected with SW freedom in mind,
• Stskeeps hinted that the tablet has an Intel GPU,
• The Register reports that Intel (!) said the tablet is going to have an Atom 37xx CPU

It looks like we'll really get an Intel GPU, great!

CPU must have 1.8GHz, 2G DDR3L-RS and drive 2048x1536 display. The best match in this wikipedia table is Z3740D, though it supports max 1920×1280, as all CPU that use DDR3L-RS do. And all of them are single channel too. Resolution restriction is most likely result of relatively low mem bandwith, since transferring just single framebuffer 2048x1536@60Hz requires 550MBytes/s with guaranteed latencies, and I guess more is needed if compositing is used. So yes, tablet do need well tested high-performance graphics stack to push pixels over spec limit )

And BTW I find it strange that we still don't have detailed hardware specs directly from Jolla and have to compile them from third-party sources, hints and guesswork... Right now most concrete info about CPU comes from what Intel told The Register. That and general silence on TJC about anything related to the tablet. I guess there are reasons, most likely they don't want to loose freedom to change HW specs without bad PR or they have some NDAs.

Update: oh well, now we have announcment from Intel.