Consoles have a limit to graphics due to the fact that consoles can only play in 1080p max where computers can go higher I think.
Ok time to clarify a bunch of stuff.
1. A full HD tv displays at 1920x1080 resolution, and yes the Xbox360 and PS3 CAN output at this resolution. The Wii can't output at HD resolutions.
2. In order for newer console games to accommodate the more detailed environments with more "stuff" at once in games, many developers lower the output resolutions of those games. This is because consoles have an extremely small amount of ram, which is basically where everything you see/is being rendered is stored. Both the Xbox 360 and PS3 have about 512 MB of ram, so this is a "good" solution to having to work with a very limited amount of ram. For example, games like Modern Warfare 2(Xbox AND PS3 versions) and Halo:ODST both only output at 600p (1024x600) which is far below the full HD standard of 1080p(1920x1080). This output resolution is the same no matter what type of HDTV you have. I dont know if Bioshock 2 does this, but nearly all new console games do this to achieve a more detailed environment with more "stuff" in game at once.
3. Yes, any computer that has a somewhat new graphic card can output at resolutions up to 2560x1600. Although just about every graphics card made within the last 5 years has the ability to output at that resolution, almost no computer monitors support it (also you need a VERY powerful graphics card to run games at that resolution). The majority of computer monitors you see now are somewhere between 1280x1024 and 1920x1200. Anything higher, and you start to see the monitors costing A LOT more, although this may not be the case, for example, I bought a brand new monitor for about $200 and it supports a maximum resolution of 2048x1152 (higher than any HD tv). The cost of a 2560x1600 monitor can be between $1000 and $3000, depending on the quality.
