I'd like to have a mechanical-switch keyboard someday; unfortunately most of the ones I've seen (including the ones in this article) tend to be full-size 104-key keyboards, while my tastes tend toward smaller keyboards like the Happy Hacker keyboard (which is excellent but uses rubber-dome switches). Right at the moment I'm using a Lenovo Thinkpad USB keyboard because it's a smallish keyboard with a built-in trackpoi…
The HHKB is very much still in production (mine just arrived last week), though it can be hard to get one in the US. I ordered mine from http://elitekeyboards.com . My HHKB is replacing a 16 year-old Apple Extended Keyboard. It's definitely not as click-clacky as a buckling spring keyboard, but it's much easier on my wrists (and doesn't wake people up when I'm hacking at night).
I realise using arrow keys is heresy to a certain subset of the programming community, but I've been using them for decades and it's hard to give them up.