You're looking to transcode MPEG-2 to MOV, right? Perian doesn't do any transcoding; it only allows playback. EasyWMV and ReelBean don't specify MPEG-2 as viable input sources on their sites either.
A shareware transcoder (but too complicated for a newb like me) is
ffmpegX. They specifically state that it +"Reads the following input formats: MPEG-1, MPEG-2, MPEG-4, .... and even more formats"+. I've not used it, so I can't attest to its effectiveness.
A commercial transcoder is
VisualHub. According to them +"... all forms of MPEG video ... are supported"+. If your viewing size is less than 640x480, you might just try their freebie
iSquint (which I use to get videos onto my iPod).
The expensive
Sorenson Squeeze lists MPEG-2 as one of their input types, and lists MOV as one of their output types. I'm not a video editor, so I know nothing about this program (other than it's a well-known one). They do have a free trial, so you can test to see if it does what you want.
As for the
Quicktime MPEG-2 add-on, it seems to be what you're looking for. According to the description +"... your MPEG-2 video content can be imported into QuickTime Pro and exported to other formats ..."+, so if you have QTPro you can convert all your videos to MOV. The posted reviews, however, don't inspire confidence, lol!