The update is for the Skin Plugin (engine) and is separate from the individual custom skins.
If you use 100% dpi in your Windows settings, then it may not be worthwhile to update. If you use a higher dpi, then it will make the skins bigger and text will align better and not overlap.
skin update
Re: skin update
Morning johnwrites,
In the interim - while awaiting Jeff's return to follow-up with you, I'll answer your inquiry above. (NOTE: I'm using Win 7 x64).
The Windows DPI setting Jeff referred to can be found as follows:
1. From your Desktop screen, click the [START] button, then click [CONTROL PANEL].
2. In the Control Panel, click on [DISPLAY]. You should now see your current DPI setting (See screenshot below).
3. To change the DPI setting, you can either select one of the preset DPI settings shown, or change/create a customized DPI setting. To make or change a customized DPI setting, click on the link shown in the red rectangle, then simply adjust the "%" number shown in the small dialog box (in the blue rectangle) in the screenshot using the arrow on the right. If you make any change to the DPI, remember to click the [OK] button at the bottom of the window. [Click on the image to enlarge]
Hope this helps.
In the interim - while awaiting Jeff's return to follow-up with you, I'll answer your inquiry above. (NOTE: I'm using Win 7 x64).
The Windows DPI setting Jeff referred to can be found as follows:
1. From your Desktop screen, click the [START] button, then click [CONTROL PANEL].
2. In the Control Panel, click on [DISPLAY]. You should now see your current DPI setting (See screenshot below).
3. To change the DPI setting, you can either select one of the preset DPI settings shown, or change/create a customized DPI setting. To make or change a customized DPI setting, click on the link shown in the red rectangle, then simply adjust the "%" number shown in the small dialog box (in the blue rectangle) in the screenshot using the arrow on the right. If you make any change to the DPI, remember to click the [OK] button at the bottom of the window. [Click on the image to enlarge]
Hope this helps.

Global Moderator
Re: skin update
If I may add, assuming you have never changed the DPI setting (which I presume is the case since you have asked where the setting can be changed) then you most likely have the default 100% setting enabled (also WIN7 example). Jeff has said "... it may not be worthwhile to update" the skin plugin.
(assuming you like how pages are presently rendered)
In which case 
Good judgment comes from experience and a lot of that comes from bad judgment. - Will Rogers