Rothrandir, several companies are already working on drop-in replacements for incandescents using luxeon stars and 5mm LEDs.
For 5mm-based lamps, one of the most notable ones is LEDtronics, who actually manufacture LEDs themselves too. They have them in all sorts of form factors (eg. MR16s, edisons, PARs...etc), but I'm not sure if they've taken care of polarity (which is fairly easy to take care of using a bridge rectifier). They have developed these LED bulbs to work on line voltages like 110/120VAC or 220/230/240VAC, so you can use them almost wherever.
There are also quite a few developing Luxeon-based lamps, like Lumidrives (who have been somewhat quiet) and aussie company, MyShowers.
Unfortunately, its early days yet, and I have not seen LED-based replacements that will rival the output of their incandescent counterparts yet, although the gap is closing. Take the average 11W PL bulb (in edison-base form) for example - it averages at least 90 lumens/watt for a total of 990 lumens from that lamp. That's more light than an M6! You'd need a lot of 5W(120 lumens @) before you could match that output.