You want a Blu-Ray Live! player to get all of the special features this will have an ethernet port and at least 1gb of storage. Depending on what you want to spend , you're looking at $160 to start. A PS3 is a good one at $299 if that is in your price range.
As mentioned before, the PS3 makes an excellent BluRay player. Even if you do not play games on it, there are a lot of other online features that you can use with it that makes it a cool addition to your entertainment room.
BluRay players come in 3 levels...
Profile 2.0 (aka BD-Live! Capable) - this version will have an ethernet jack on it (some more expensive ones might have wireless network support too) PS3 is one of these - this will let you access all the special features on BluRay discs, like online games, chat during the movie, bonus features available only online, etc.
Profile 1.1 (aka Bonus View capable) - I think this is the lowest level commonly available new now. Bonus View refers to a special Picture-in-Picture type special features. (An example of this is the commentary on the Sleeping Beauty BluRay, where you see the movie with extra art work that is referred to in the commentary track overlayed)
Profile 1.0 (Basic) I dont know if they still make new ones of these. My player is 1.0 and I don't feel like I've missed out on much, but certain games and bonus features will not play on this - regular bonus features, like making of materials and stuff play - so don't worry.
Thus far, I don't know anyone that uses the BD-Live stuff on any of their discs yet, but having it for future-proofness might be good. Do you have a high end TV and/or sound system? If not, you can probably get away with a bargain model. My brother has had a Sylvania model he bought at WalMart for about 6 months, it's Profile 1.1 and works fine and looks great on his Vizio 1080p LCD tv. I have the earliest model Sharp Player (profile 1.0) on my 720P Panasonic Plasma and it looks amazing. I bought it because my recceiver does not have HDMI in for audio, and the BD player has 5.1 analog out for my audio system.
Sure, there are few $5 blurays now, but the Disney movies, for example, aren't gonna be that much more when they come out than the DVD's will be. With a $10 coupon from Disney I'll be getting Snow White for about $17 ... not bad at all.
I have a question about blue ray players as well: inasmuch as there are recordable dvd systems, are there blue ray systems also that are recordable, or are they not yet available?
There is the JVC SR-HD1500 Blu-ray recorder (Not for home use @ two grand) The Sony BZD series starts at about a grand - but haven't left Japan yet. For the under a grand department there is the LG HR400, but it may not be available outside Europe.
Most folks just buy a Blu Ray burner for their computer for $200 to $500 and work from there...
I don't know what you mean by hidef. I have HDTV and HD satellite programming w/HDDVR. I don't own Blu Ray so I wouldn't know about hidef discs running on them. All I know is if I get a Blu Ray player I can plug it in via HDMI and all is well.
I know folks who burn their HD camcorder output and HD programming from their HDDVR's on to Blu Ray so I guess that is some kind of compatable.