I just bought a 1080p Panasonic plasma (hd inputs, etc.). I have a decent-sized collection of standard-definition dvds. Right now I have no way of upconverting them to HD. My questions is this – should I purchase a) a blu-ray player to upconvert my sd dvds for viewing on the 1080p plasma, or b) should I buy an a/v receiver (I’ve been looking at the onkyo sr606) to do the same job?

If I went the Blu-Ray route, I'd connect the player directly to the TV via HDMI. if I went the receiver route, I'd connect my old Toshiba (SD) Dvd player to the reciever via component cables, then the receiver to the TV via the HDMI.

Are there are advantages or disadvantages to either setup that I'm not taking into account?

Thanks!

I would buy the blu ray player and pass the video directly to the tv

You should do A and B.

Why don't you just play them in your DVD player til you decide? Because they WILL be upconverted, the TV will do it.