The second update for the PC version of BioShock 2 has been released today, fixing the widescreen issue which caused field of view to expand vertically rather than horizontally for those with widescreen monitors, as illustrated below.
After updating, the game will expand like this.
2K previously said it feels "silly" about this, particularly given the same problem occcurred with the prequel. Anyhow, they've been quick to patch it, so all's well.
In addition to that, the patch also fixes an issue where the M1 button would not register in multiplayer.
Grab it now through Games for Windows LIVE.