I think you just answered your original question. Stick with DVD until you have a reason to go Blu-ray; probably couple the purchase with an HDTV.
Updates and firmwares will continue and if you don't buy now, the player you buy later will have more and better features.
For instance, a friend of mine bought a Sony Blu-ray play shortly after they came out; he has a $25K projector setup so I don't blame him for wanting quality. But that player is very slow and takes upwards of 2 minutes to load a disc to the menu. My Samsung bought Nov. 2008 is closer to a minute; probably less but I've not timed it. ASICs will get faster so we can hope that load time will decrease with newer units.
Also, more and more players have added features like the ability to stream Netflix or Pandora, both of which my Samsung can do but my friend's Sony cannot.
My Samsung has Ethernet for BD Live; newer players have added WiFi to eliminate the need to provide wired connectivity.
Prices should continue to drop as well. While it will take a long time for BD players to become as cheap as DVD players are today, the gap is narrowing. And DVDs are still cheaper than equivalent Blu-ray discs, although some BD releases are including standard DVDs as well which is nice.