I'm another sad/mad owner of a Toshiba 65HM167 with the white dots from a failing DLP chip. We obtained it new late in 2007 and the first bulb lasted until Jan 2010 under fairly heavy use. Sometime earlier this year the first few white dots appeared, and like others have stated, once they start, they multiply fast. That second bulb lasted until Nov 2011 (this month - blew just before the Pacquiao vs Marquez fight), so I was debating replacing it because of the white dots. Local TV repair shop said it would cost me less to just buy a new TV (with $200-$500 credit for this one, depending on what I get, and they finance, heh).
I went ahead and got the second bulb for $118 from discount-merchant.com, where I got the first one for $163, Toshiba Y67-LMP Replacement 75007091. Their warehouse is in the Otay area of San Diego, just off of the 905 at the last U.S. exit, within driving distance. The bare bulbs came wired with the connector, and it was very easy to swap the bulb housing, being careful not to touch the bulb surface. The new one has a different style fuse in it, and thicker wires, but other than that it looked the same.
I found the replacement DLP chip 4719-001997 at shopjimmy.com, as suggested in another post, for the special price of $215.16 (regular price is $349.95). It was in stock Friday morning, but when I returned from picking up the bulb, it was no longer in stock

. I have some electronics experience from the Navy, and build my own PCs, so I was planning on getting this chip and hoping for another 4 years of life from the TV. I signed up to be notified when it's back in stock, but wonder if they will ever carry them again.
Some stats I pulled off the service menu (I've never reset them):
Power On: 12,384 hours
Lamp Low: 5,874 hours
Lamp High: 6,510 hours
Lamp On Times: 5610
Temp1: 40° C
Temp2: 44° C