Whoa! I was not aware that these are actually settings. I thought that this dialog:
http://img.gameru.net/img/58f26.jpg
...listed only video driver capabilities. However highlighting one of the rows DOES indeed change the respective setting. This dialog really should be re-designed using checkboxes!
Anyway, your tip already helped on my desktop with an AMD Radeon HD 7700 card. Same on the notebook -- when the Intel HD graphics card is chosen for driving Sketchup.
However, when I chose the Nvidia GPU from the Nvidia control panel for powering Sketchup, all the settings in the OpenGL section of the above dialog are ignored. I mean, there are those different rows with different Antialiasing capabilities (like 2x and 4x), but when highlighting one of them, closing that dialog and re-starting Sketchup, lines are still not anti-aliased but look like this instead:
http://i.imgur.com/wFIfoPp.png
Is there anything else I can do to force antialiasing not only on the Intel HD GPU but also with the GTX 860M CPU?