4Sevens just released a new line of flashlights now available in S2. As far as mass production goes, the LED's are "rarer than hen's teeth", and wont be available for at least a couple more months.
Would you even notice the difference over an R5? I bought a pair of XP-G R4s and they don't seem any less bright compared to my R5s. They blew away the SSC P4 U-bins that they replaced, though!