Will this drive work in a regular desktop PC?

Only if the motherboard or an add-in card has a SAS controller. Standard consumer SATA ports cannot connect a SAS drive, and a simple SATA-to-SAS cable will not work.

Is this drive new or a refurbished pull?

That depends on the seller. Dell enterprise drives are often sold as new, as factory-refurbished, or as pulls from decommissioned servers, so check the listing's condition before buying.

What Dell servers is it compatible with?

Compatibility is tied to the exact Dell part number and the server's drive carrier and backplane. Match the part number to your PowerEdge model's supported drive list before ordering.

How does it compare with a SATA drive of the same capacity?

SAS offers dual-port connectivity and is built for continuous server duty, while SATA is cheaper and plugs into consumer boards. Raw capacity and spindle speed can be identical.

Is 2 TB enough for a server today?

For boot volumes, logs, or small arrays it is fine. For bulk storage, larger enterprise drives pack far more capacity into the same bay.

Does it need a special cable or backplane?

It uses a standard SAS connector, which is physically compatible with SATA-style cabling on the drive end, but the host side must be a SAS controller or backplane.