Yup, you can stream BR level content. But you'll need to be careful ...
1. Use wired ethernet if at all possible - gigabit will give multiple streams, but 100mbps will do nicely for one room / tv at a time
2. Bluray over wifi is possible (despite what you often read), but you'll need decent kit - 802.11g is out, you need MIMO 802.11n (300mbps+). We happily stream BR over Wifi to the XBMC box in the kitchen, but had problems with the inbuilt wifi (despite it being 802.11n). I now use a dual band Buffalo Wifi bridge that keeps a solid connection to the access point two rooms away.
3. Band - if your house is detached/well spaced, 2.4GHz is fine and handy for range, if you live in a flat / terrace you'll probably need to look at 5GHz kit to avoid the baby monitors. Quality matters.
From my experience, you need a constant 8-9 megabytes per second throughput for clean BR - that's about 80mbps (meaning over 150mbps with overhead). Kit varies a lot - my dual band Apple Airport extreme from a few years back managed that easily - the last one I had (modern simultaneous dual band) was hopeless. Most good laptops wil throw 6-7 megabytes a second over Wifi ... mine normally tops out at 12-16 megs but I sat in bed last night copying at 27-28 megabytes a second from a Cisco E4200 in the room below to my HP (Intel 6300 extreme card). Normally only top-end corporate kit has these types of adapters and the necessary aerials.
YMMV