Adobe:

We’re pleased to announce that Lightroom 4 is now available via the Mac App Store in North America.The Mac App Store offering is the same product offered on Adobe.com in terms of features and functionality but has been modified to comply with Mac App Store requirements. There are a few important pieces of information you should be aware of.

It’s $149.00, same price as if you buy it at Adobe.com but there’s no upgrade price if you own previous versions of Lightroom (there is if you buy it from Adobe.com). The Mac App Store version is for Mac OS X only – the version you buy from Adobe.com is Mac and Windows. The Mac App Store version can only be updated thru the Mac App Store. Adobe says that means they could update it on their web site but it may not happen at the same time, or at all, on the Mac App Store.

There’s more.

Adobe says there is no guarantee that upgrade pricing will be available to Mac App Store Lightroom 4 customers when Lightroom 5 and future versions of Lightroom are released and that Lightroom 4 is available only on the Mac App Store in North America.

Remind me again what the advantages of the Mac App Store are, Adobe?