Discussing how profitable Blu-Ray has been for Sony is an amazingly difficult thing to calculate because so much of their revenue from Blu-Ray is interconnected with other things; Blu-Ray benefits Sony's electronics division because it provides a High-Definition content source which is one of the main reasons people are/were reluctant to buy expensive HDTVs that have massive mark-ups, it also benefits them because their movie studios can "remaster" and re-release every "classic" movie which has high margins (if volume is high enough), and Sony also gains because they receive licencing fees for every disc or player sold.
Depending on how you account for the losses in the Playstation division, the monetary transfers to get exclusive studios, and whether you include revenues outside of raw licencing fees will impact how you calculate how profitable it is. Personally, I don't include electronics revenues or revenues from moive studios because (without Blu-Ray) a HD medium was going to be available anyways; at the same time I do include the losses in the Playstation division and monetary transfers to movie studios because this money was spent (primarily) to make Blu-Ray successful.
Right now, Blu-Ray licencing fees on hardware and discs are probably fairly high but so are the costs on the technology licences that make up the Blu-Ray format; and over time these licencing fees will be (drastically) reduced until you can sell a Blu-Ray player for $15 and a Blu-Ray movie for $5 with packaging and turn a profit. The Blu-Ray consortium is also facing massive marketing expenses as they try to make the format more popular, and the "profits" are split across a large group of companies, so the per-company revenue from Blu-Ray is probably tiny at the moment.
Ultimately, with little revenue comming into Sony from Blu-Ray along with massive debts from Blu-Ray I would say that it has been far from profitable for Sony.
