As for the dvd replacement:
* No idea what you could get as a replacement
* I doubt that removing the drive would void the warranty, HP usually lets you replace most of the stuff w/o losing warranty (although the DVD drive is the only part that has no mark symbols beneath the screws)
* the mentioned HDD bay for the MultiBay slot does NOT fit in the 2510p. I removed the DVD drive and made a photo of its connector:
http://pub.jay2k1.com/2510p-optical-drive-connector.jpg
This is definitely not the kind of connector that can be seen on the eBay auction's pictures.