I second the advice of unplugging everything from it and letting it dry out for a week. After a week turn it on and see if everything is okay. If you smell burning plastic or see smoke, the reciever is most likely toast.
For a new receiver I would recommend the Marantz SR4600. It is their lowest price model, but it is the best all-around 7.1 AV receiver (and I believe it can play a second set of speakers).
From
www.marantz.com:
SR4600 Dolby Digital EX®/DTS ES® Surround Receiver | $429.99 (MSRP)
80 Watts x 7 Channels All Discrete Amplifier Stages
Dolby ProLogic IIx/ DTS 96/24
32-Bit DSP
192kHz/24Bit Audio DACs
HDCD Decoder
Surround Speaker "B" Output
Detachable AC Cord
Aluminum Front Panel
I purchased the SR4500 ~ 1 yr ago for $299.00 (when it was being discontinued) and am very happy with the performance.
Best of luck,
John