Is there a way to convert my DVD's from .VOB to the new .WTV or is it better to use dvr-ms?

I'm not sure if there a way or not. There isn't a way to convert h.264 to wtv, but either way, dvr-ms is just fine.

 There really isn't any reason to use wtv over dvr-ms. VideoReDo TV Suit is the easiest way to convert DVDs to dvr-ms, but it isn't free. You can also use todvrms to convert to either container, but you'll have to convert the vob to mpg first.

From what I have read at videoredo's forums, there is a large difference between encoding to dvr-ms and wtv.  The wtv container has been giving them a lot of issues, but I believe they are still working on it.

Chip

 Todvrms works just great and is open source. They should ask Andy about leveraing his work for VideoReDo. (Andy's has worked for like 8 months).

Todvrms is extremely buggy in 64 bit now.