Year of remasters
This year actually saw quite a few of these re-releases for games. Retouching a game's graphics a bit and making it compatible with the newest generation of consoles allows publishers to cash in again with fairly little effort.
Not all remasters make it to the PC platform since the old versions are often still working fine. That does not always stop the greediest publishers from trying to resell their slightly reworked games at full price, however. (Alhough I cannot name any from the top of my head.) Then there are remasters that are offered at a discount if you already own the original game on Steam or such. And finally some are simply given at no additional cost -- like BioShocks 1 and 2. (BioShock Infinite did not get a beautified version on PC and it certainly did not need such.)
Mostly just higher definition textures
A series of developer commentary videos were added to the first game as well. They have to be unlocked by finding each clip in the game. And it is quite easy to miss many of them. But I think you can also simply edit an .ini file to set each video's unlock value to true.
I would have maybe preferred more Deus Ex: Human Revolution - Director's Cut style commentary where the developers were seeing the actual game and had easier time to remember what was going on at different locations. Instead, the commentary in BioShock Remastered is just Geoff "Dorito Pope" Keighley interviewing creator director Ken Levine and lead artist Shawn Robertson and injecting in his own opinion of what BioShocks are about. Regardless, it was fascinating to listen to Levine and Robertson talk about where stuff originated from.
Plethora of technical issues
The remasters are not without faults. Or at least were since there have been two patches to them now since the release. The first one added very much needed FOV sliders. The solution before that was to add a custom keybind for adjusting the value but it had a similar problem to the fix in the first Borderlands game where certain actions reset it back to the default. In this case merely aiming down sights would require you to press the bound FOV key again.
I saw many complaining about the games being unstable and not even running. On my first playthrough of BioShock Remastered I did not have the game crash even once. But when I did another run after the first patch to get remaining achievements, the game crashed quite a few times. I even found a spot where the game would crash every single time. Going back down to my monitor's native resolution from 4K allowed me to get past that point, though.
Blind Squirrel Games -- the studio responsible for the remasters -- definitely seemed to have put even less effort on the second title. It is possible it works better now after the December patch, although I have my doubts.