When is it safe to buy a PS3?

[Jodi]

With the PS3 available now, of course the first generation units are going to have "bugs" in them.
Over the past one week, a local Wal-Mart one day had 3 PS3's -- they all sold out. Today, they had 4 PS3's in stock.
I want to buy a PS3 exclusively as a first Blu-Ray player, and I am aware that there will be more firm-ware upgrades in the months ahead. I plan to hook one up to an LCD TV like Sony's BRAVIA XBR 2 line (the 32" model).
My question: when will be a good time to buy a PS3?? Any guess as to what months this year, as well as the second or third or fourth generation PS3 models as 2007 goes on.

Thanks,
Jodi