"Big" being a highly,
highly relative term, at this point. As you probably noticed, blu-ray anime releases were still somewhat of a rarity throughout 2008. But even so, according to a survey picked up by
ANN, anime titles accounted for 64% of all Blu-ray Disc sales in Japan during September. By that time, their local BD market had grown by more than 350% since the beginning of 2008. When compared with the DVD market for the same period, the report points out that the Blu-ray Disc market was 0.9% the size of the DVD market in January, and grew to 3.8% of the DVD market in September.

This steady increase was due in no small part to anime titles such as
Code Geass R2,
5cm per Second,
Gundam 00 and
Macross F. The latter, in fact, sold more copies on Blu-ray, than on DVD. And as a general trend, anime releases topped the Blu-ray sales charts during the year, at times even
completely monopolizing them.
By the end of the year, the market is expected to amass about 700 titles and 5 billion yen (US$50 million) in sales. Still,
the best is yet to come in 2009...