Before I go and drop a PSoC into a new design :-P , I thought I should check with the well-informed (8051) masses.

I need a part that will interface with some legacy 5v electronics (Analog Devices D/A, 4000 series CMOS, and some discrete electronics that I have no control over). What I would like to have in an 8051 is a flash micro in a low pin count package, but not too low. ;-) I need about digital 21 I/O pins plus a UART. I would like the part to support a flash boot loader and it must be physically pretty small, since it has to fit on a board about 0.5" by 1.5" yet not require exotic soldering methods. I can handle various surface mount, but not BGA or those ones with the pads underneath (QFN/MLF). Unfortunately some older PSoC parts fit the bill.