Note that I did say widgets, not app icons, though according to early tests, it's still icons that are being added and not widgets. This option appears in place of "auto-add shortcuts" that is present in the current Market and not in addition to it. Did Google simply rename it for some very confusing reason? Weird...
This explanation makes sense, though Google could have been smarter about the naming convention for devices that don't yet have Ice Cream Sandwich.
There could be other changes, which we'll post as soon as we find them.
This post by Kirill Grouchnikov from the Android team provides some interesting details about the evolution of the Market. It's not related to this specific update, but is an interesting read nonetheless.
Download the new Android Market 3.4.4:
Note: Root is not required.
Note: If the Market starts force closing, just open Settings > Applications > Manage > Market, and clear data.