In a weaker version of that sense, the MSP430 is also "unbrickable": as long as you don't touch the default BSL and as long as your code leaves the write-protect alone, everything is fine. The problem is that an inexperienced user (or someone who types command-lines on autopilot) may easily reflash the BSL.
AVRs are definitely the strong version though; they have hardware write-protect for the bootloader that as I understand it can't be overridden without connecting up a programming cable, and neither can anything else that would prevent you from booting from said bootloader. At least that's the theory...
Actually, you shifted what I wanted to say where a bit: I meant that while the current FPGA can do 3.3V, I am not sure how many others can do so.
Ah, sorry. Well, Cyclone IV and earlier can, as can Spartan-6 obviously. Kintex-7 and Cyclone V will apparently also support 3.3V IO on at least some pins, though I'm not sure if they do for the configuration pins...