It seems like it's a localization string identifier, which means it probably stands for a tangible product, and it seems strange that a developer would randomly add and commit that change.
I'm going to guess that it was a mis-merge in the App Store codebase and that Lion will be able to run iOS apps (using the MacBook touchpad or Magic Trackpad for multitouch). I mean, Snow Leopard already runs iOS apps pretty much natively if you have the SDK installed.
If it's anything (it's not, but it's fun to pretend), it could be a sign of integration between the Mac and iOS App Stores. Even if one isn't actually being rolled into each other (which I would assume they wouldn't be unless iTunes was redesigned), it could just be saying "this is also available as a Mac app," possibly with a link to the Mac App Store page.
I have no experience in submitting Apps to the App Store, so I might be talking rubbish. But one could simply submit two binaries - or linking to the Mac App Store version, as suggested in another comment.
It`s like a bundle; pay once, run everywhere. Cultured Code`s Things for instance could sell such a bundle with a discount.
Some people do that already for libraries that work on the simulator and device. It's a bit of a pain in the ass to do manually, but it's not something that would take apple long at all to add to the toolchain.
I'm going to guess that it was a mis-merge in the App Store codebase and that Lion will be able to run iOS apps (using the MacBook touchpad or Magic Trackpad for multitouch). I mean, Snow Leopard already runs iOS apps pretty much natively if you have the SDK installed.