Further evidence of BioShock: The Collection has appeared (and then disappeared, the page is no longer there) from the 2K website. It was accompanied on the server by some box art (below), which is all a pretty strong indication that the compilation of titles is on the way.
Just to add a little more evidence of the circumstantial variety, 2K were urging everybody to follow a newly created BioShock twitter account.
Back in April, the ESRB rated BioShock: The Collection for PS4, Xbox One and PC; so unless that was inaccurate or things have changed (the ESRB page vanished after being found too), then we’ll be getting a PC version.
The compilation is said to include BioShock, BioShock 2, BioShock: Infinite and (according to previous retailer listings) all the DLC for those games. In terms of PC-related improvements, the first two games would probably benefit most from a re-release (BioShock never had proper widescreen support, for example, so that’s something which could be fixed). At this stage though it’s not known what (if any) changes will be made for the PC versions.