This is a rapidly evolving market. My intent is to wait a year or two for these things to shake out, then go for it.
I am in the same mode but Doug sounded desperate

I am no expert on these but am interested as I plan to rewire my new old boat and replace all 12-volt lights with LEDs. The market for 12-volt LED bulbs seems to have exploded and most bulb types are available from local chandleries.
In the AC world, it did look a little dicier, but searching on "LED halogen replacement bulbs" turns up items on Amazon and elsewhere that don't seem overpriced and which (to the extent they are not shilled) have gotten some decent reviews. Like:
http://www.amazon.com/LED-MR16-Spotlight-3-8W-Lumen/dp/tech-data/B003Y24V38But caveat emptor. I'll be interested to hear other people's experiences with these.