I havent heard of any unusually high failure rates either, compared to the rest of the industry Western Digital's generally had fairly good RMA rates the last 0-3 years, though they had a few years prior to that in which their previously exceptional reliability went straight down the drain.
On a personal level I don't deal with the "JB" series of drives frequently enough to make any comments but the mainstream "BB" series based on the same technology have had very good failure rates, so I'd be somewhat surprised if the situation was reversed with the "JB" line.