one thing, all these ppl singing the praises of HL, in both SP and MP capacity, lets face it HL in SP is very good.
HL in MP, no mods, is boring, its a sub standard version of Quake DM, and when i say Quake i mean the original quake, the only version of quake worth playing online really. Q2 and Q3 just watered the gameplay down really
HL is good in MP with its mods, so once JK2 gets some mods on the go whos to say it wont be better than HL? i would like a TFC style (i know ppl will probably jump on that, but i said style not copy) mod, rebels vs imperials, classes like jedi, gunner, trooper etc. it would be really cool.
the thing JK has behind it, is a wealth of familiar background material, that is i guess familiar to virtually most people on the planet.