2K has said that a PC patch to fix BioShock 2's widescreen issue should be available at 2am PST today, which is 10am GMT.
According to the Cult of Rapture site, this fix was prioritised due to the number of requests for it, and will be followed by a more extensive patch in due course.
In its initial state, BioShock 2 would display letterboxed versions of the 4:3 ratio image when put in 16:9 or 16:10 resolution.
Earlier this month 2K blamed this on a "last minute bug fix", admitting that it felt "rather silly" about the whole thing - not least because it's the same problem BioShock 1 had.
The new patch will also fix an issue "where holding the M1 button would not register in Multiplayer gameplay". Presumably that's the left mouse button, or else my keyboard's getting old.