I got a reply today from Akai regarding their MPD-16 controller pad. The rep gave me the green light and said "yes" they can also be used for synths (or any keyboard that has midi)

I'm going to buy one. For $99.00 it's a minimal investment, and will be a great addition to any keyboard for drum programming.

For those here not used to touch sensitive pads (like those found on drums machines) I can honestly tell you that the result will be quite pleaseing. With a keyboard you have to wait until the key returns--even though they're synth action, but if you're recording a heavy and fast drum loop then your keys can often take a pounding.

With rubber touch sensitive pads, you have a better connection with the sound (at least I feel you do). Personally I think the end result using pads as opposed to keys is more favorable.

Squeak