xhp are the latest craze for insane output, but they require higher voltage, so you have to have the appropriate driver for them.
xpl and xpl-hi are the standard for small format lights. xpl-hi being a flat dome led so it helps with throw. and xpl being the size of xm led (xml, xml2) but has the same footprint as an xp (xpg, xpg2). Nichia 219b is the defacto standard for hi-cri goodness.
Other than that, just some new custom builders, but I have to say not quite to the extent as in the past. Although I will have to say that with vinhnguyen54 around, you can get almost any manufactured light upgraded and get it to put out some insane output. Also, Vestureofblood and Tana are doing some very nice upgrade services for Surefire lights. Dan and Tom at Oveready are still around and with their v5 triple light, you can program using anything with a screen, including a smartphone. Very innovative.