This doesn't appear to have been mentioned yet, sorry if it already has.
Texas Instruments who make DLP chips have just announced a breakthrough in projector technology - the first lampless projectors!
The light will come from three LEDs (red, green, blue) which can switch on and off incredibly quickly. This will mean an end to single chip DLPs 'colour wheel' and potentially an end to RBE (rainbow effect), though it's unclear at the moment, and until a review model appears, if this is a complete defeat of RBE, or just a limitation of it.
There's considerable discussion as to whether the unit will even need a fan. If a fan is needed it's possible that it'll be less important, and hence slower, quieter, and chucking less heat into the room.
Finally, as there's no lamp, you'll never need to change one. Ever! And the LEDs will not dim during the unit's lifetime.
Anyone else excited?
BTW, downsides are that LEDs have so far not been bright enough, so it's likely that the first models won't be the brightest on the market. Also prices will be higher, though it looks like only $200 or so more per unit, or about the price of one replacement lamp.