As to 2.0... It refers to the version of the specification. Currently BD-discs and players are version 1.1-compliant, with 2.0-compliant version becoming available later today (PS3 will just need a software update though). But that doesn't mean that existing players and/or discs become obsolete. 2.0 just deals with extras and their features.
There are few 2.0-spec discs out there, and while there are no player that can take advantage of the extra features at this moment, in few months time there will be. IF you have a 1.1 player that can't be upgraded to 2.0, there's no need for alarm, 2.0 doesn't bring any "must-have" features with it.