When, if ever will blu ray drives become standard.

[Alby_da_Wolf]

^^
SSD is not cheap and flash sticks cost per GB is higher than discs, so as soon as drive price gets low enough BD will be attractive for a large enough subset of storing needs. Both SSD and flash sticks, anyway, already have an edge right now over rewritable discs, as the latter are way too slow and expensive enough to make flash preferrable for their speed even at a slightly higher cost. BD-RE IMVHO will be a sensible choice only as a better heir of VHS cassettes compared to the slow, awkward and too small DVD+-RW, so only for stand-alone recorders and almost nothing else. For other uses I see a combination of different tech as ideal: USB HDD fast and cheap, very high capacity, SSD fastest and expensive, medium-high capacity for uses really needing the fastest option, BD-R, permanent storage of medium capacities, DVD-R, cheap floppy heir and smaller backups, Flash stick, fast and practical floppy heir.
This said, BD isn't ready yet for PC mass market, still too expensive and slow, for the PC I finished building some days ago I still chose a DVD burner, I have enough disk space on internal and external HDD's for when DVD is too little or too slow, I too use a Flash stick and find it very useful and practical, although not a solution for every need, and I won't buy a BD burner before it's under 50€ VAT included.