The Mac App Store should revolutionize the way that Mac user buy and install applications, one simple click will purchase and install the app that you want, within seconds it will appear on your doc.
Apple’s App Store for iPhone, iPod Touch and iPad has been a huge success thanks to its ease of use and fair prices, therefore I am sure that a Mac OS X equivalent will be a very popular addition, personally I am looking forward to see how the Mac App Store will improve OS X as a gaming platform, because at the moment it would be fair to say that it is nowhere near as accomplished as Windows.
If you would like to develop Apps for the Mac App Store you should check out this link, you never know your app / game could become as popular as Angry Birds or Infinity Blade, which will undoubtedly improve your financial situation in 2011.
What do you want to buy from the Mac App Store?
Also See: iOS 9 OTA beta 3 update notes live