I'm not sure there's much difference between "consumer" and "server" grade drives these days anyway, except pricetag.
Most servers drives are based on consumer ones, just tuned for server tasks. And longer warranties, of course, perhaps that's why the pricetag.
This can't come in a worse moment for Seagate, with the 7200.12 drives just around the corner (including 2TB units) and the change of CEO. Couple that with the current economical crisis and all the competitors doing better than then, and I think you can say Seagate is going to face a tough year.
It's quite peculiar tough, that the 1 TB models started failing precisely now, after one year or more of being introduced in the market. The news about the 1.5 TB unit failures appeared just weeks after they started selling, and based on what nosh said, it's probably more of a really bad batch than a general problem with all 1 TB drives.