The blog mentions that these $10 plans are on the "new" hardware, which, AFAICT, doesn't allow access to shared [unused] cores on the host anymore, so you really do have only 1 core max. FWIW. They're said to be nice speedy cores, though I've never tried one myself.

Anyway, it's nice to see linode finally come down in their price point, thank goodness for competition, they're obviously responding to DO with this move. Unfortunately the $5 DO is good enough for me [SSD makes is so that swap time is less painful if I temporarily max out the RAM] so, alas, will be sticking with DO for now :|