Is Blu-ray here to stay?

[ps3bd_owner]

Watching films and series in HD on Blu-ray (and for this matter also HD-DVD) is pretty damn enjoyable, but I was wondering if BD will at some point become obsolete?

I know that once there's better tech the inferior will phase out, but people invested on Blu-ray and companies too so it's a shame to discontinue it.

50 GB discs should be more than enough for HD films and series.

P.S.: DVD is still alive, a couple more years and then that's it, I suppose.