There are pros and cons to both approaches. Considering pre-pros can cost as much as mid level AVRs the cost benefits are questionable. IMO, nothing new is going to happen with respect to formats and connectors for a while, so the whole flexibality argument is also weak.
IMHO, the only argument that has any merit is, that a good amp can be kept for as long as it works. And, it is awesome today, it will be awesome until it fails.
If you have enough inputs and outputs, and after getting the BD Player dont intent to change your setup in the foreseeable future, get an AVR. Also, most mid level AVRs offer features only available in high end pre-pros (net audio, audessy, etc.). Almost all AVRs give you a powered Zone 2 and some even give dual HDMI outs.
Further, the main reason for getting a dedicated amp is to have an amp with enough headroom. The SVS speakers do not require a dedicated amp to drive them and you will exceed the speaker capability before running out of headroom on a good AVR.
Bottom line, get an AVR.