While Funimation initially released the show on DVD, they did not have the Blu-ray rights. Aniplex of America was then founded not long after and Baccano!' S Blu-ray release was one of the first titles they had announced (alongside R.O.D. And Rurouni Kenshin).
The Blu-ray was originally released as a Limited Edition Blu-ray set which contained packaging very similar to Madoka Magica but in Blu-ray size and only a few extras. It later sold out and was re-released as a standard Blu-ray set, which I have right here.
Baccano Manga
This standard edition Blu-ray set contains the entire series (13 episodes and 3 OVAs) across three discs and comes with some small additions like a mini-booklet and a slipcover. This is one of Aniplex's well designed sets since the cover is really cool (and is the exact same as the limited edition set) and has a well balanced content of discs. Note that the discs are exactly the same as the Japanese version as it also provides Japanese subtitles. The set comes with English and Japanese audio and unlockable subtitles. Like all Aniplex sets on Blu-ray, it's region free.
Baccano Anime
In 2014 (given this is an update to the original post from 2013), Anime Limited have announced that they have the Blu-ray rights to Baccano! And will be releasing the show as a Collector's Edition package (not to worry a standard version will be available). The difference between this version and the Aniplex release is that all of the extras that Funimation included in their DVD release will be included in the UK Blu-ray release which adds some extra touch. I may consider it depending on how well the packaging and quality control is like.