As a consumer I have not bought a Blu-ray player yet - I think that it will still be some time before the technology settles. That said, I am intrigued by the BD-J Java programming environment for Blu-ray and something that I would like to look at. About 8 years ago I wrote a set top box emulation in Java for Disney, perhaps similar to what people may do in BD-J with custom directory viewers, ways to annotate material, etc. Who knows what smart developers will do with the platform? Not me.
I am turned off by the extremely high cost of writable Blu-ray media - yuck! The prices will come down, but by how much?
Massive personal storage does not (yet) excite me. We have hidef satellite TV with a hidef DVR, but we don't need to store too many hours of video, and there is nothing so far that we want to keep around for more than a week. My brother owns 1500+ Blu-ray, HDVD, and DVDs and he takes great pleasure in owning entertainment media. My wife and I prefer renting (NetFlicks) and time delayed DVR viewing. It is easy enough to re-order a NetFlix movie in the future if I want to watch something again.
I still find the storage on a DVD-R to be great for most of my uses, especially since I often compress backup data before writing. If you deal with a lot of text, like I do, it is amazing what fits onto a DVD-R.