Well, the excuse that a PS3 is cheaper than a Blu-Ray player might be a valid one. The only flaws I see are:
a) I don't have a high-res TV, my TV is a 4-year-old 42'' plasma screen with no HD whatsoever.
b) I really don't think DVD quality is outdated yet, I could handle it for a few more years.
c) Well, I download most of the movies I watch, and sometimes those 700MB files suit me just fine. Goold old Xvid/DivX still has it's charm.
I WILL buy a PS3, but only when there are good games (not great games, I settle with good. GTAIV is probably the first game that I consider to be good, perhaps MGS3 as well, but a console needs more than just 2-3 good games) and the price seems a little more reasonable.
If you are loaded with money, however, sure, getting a PS3 sounds like a reasonable thing. You can probably place it next to the gold statue you have on your swimming pool or something. It's not like it's gonna set you back or anything...