There's little sign yet of software being distributed on Blu-ray, and unless you have a huge screen, watching high-definition movies on your PC will offer no advantage over DVD.
So while a Blu-ray drive might not seem like a must-have for the average PC user at the moment, this is ignoring its potential for backing up your data.
With a capacity of up to 50GB (for dual-layer disks) it'll take far fewer disks to back up your system than if you were using DVDs. You'd still end up with quite a stack of disks if you back up a complete 1TB hard drive, but in practice most people will back up much less than this.
The BDR-203BK writer is pretty comprehensive in the types of Blu-ray, DVD and CD variants that it'll handle, and it offers an unrivalled 8x BD-R write speed (2x for BD-RE). At the moment this is a bit of future-proofing, though, since the fastest BD-R media you'll currently find is 4x.