David Pogue wrote today about the 15,000 apps now available in the iPhone app store.  It’s pretty amazing.

But where’s the app store for Mac and Windows?  

Buying apps on-line is not a new concept:  I’ve got a handful of “indie” apps that I use regularly, and many big-name apps can be now bought on-line.  But Apple’s nailed the user experience for shopping and purchasing:

• User reviews.  Gathered in one spot, on the “buy” page, just like Amazon.
• Streamlined purchase & install flow.  Enter your iTunes password and you’re done.  Compare this to filling out an order form, entering payment info, confirming, downloading, opening the download, starting the install, going through the install wizard, and launching the app.
• Enabling small value purchases.  Apple has enabled the low-price, high-volume app.

The same thing should exist for Mac and Windows.  

User reviews and “most popular” would let the best float to the top of the charts.  A standardized store would supplant the proprietary download/install modules (e.g. Adobe, EA, Valve/Steam, etc.).  The rev share with the store operator (currently 30% for the iPhone) would be lower because it competes with other distribution methods.

But it’s something only Apple and Microsoft can pull off — it really needs ubiquity to work.  (But Apple might be able to do it for Windows, if they bundled the app store with QuickTime/Safari).