OK, got my answer! Curiosity got the best of me, so I backed up my copy of v3.1.9 and installed the new 3.1.10. Previously, folders had a solid gray background and a Windows-like appearance (i.e., thin outline border with a drop shadow). The new folders, when opened, are borderless with a black, semi-transparent background. With the old folders, you changed the folder name by long-pressing the title of the open folder. The new folder design has a separate pencil icon (next to the 'x' to close) to accomplish the same task. I don't really see it as an improvement, it's just different. However, this version does have ICS and vertical scrolling improvements (neither of which I use).
Unrelated to the folder change, but I also noticed a slight improvement in memory usage with the latest version:
OLD - 29.03 / 360.87 (MB idle / peak)
NEW- 28.86 / 360.09 (MB idle / peak)
Measurements were taken immediately after a reboot on the Infuse 4g.
Also,the new version continues to show in Market as "not compatible" on the Galaxy Tab 10.1, even though it continues to work perfectly. Google and the developer were both notified (months ago, back when v3.1.9 first came out), but no apparent action has been taken.