I'd intended to wait until 5 pm GMT because that's when the store was rumoured to be opening. But I thought I'd have a quick sneaky peak at 2 pm and found the store open and doing business. Up to now I hadn't been clear exactly how the store would work, but it is straightforward. As you would expect from Apple. The store is accessed via an application that appears immediately in the dock. Simply update the Mac software and you'll find the icon sitting in your dock. You can, of course, delete it from the dock in the normal way if you wish; personally I keep a minimal dock and use LaunchBar to find my software.
It all looks very promising, with many free apps but the majority carrying a price tag. OmniFocus is there at £44.99 while the same company's OmniPlan is one of the most expensive apps at £84.99. One surprise is the attractive price tag of £44.99 on Aperture which, I seem to remember, cost over £100 only a few days ago. I notice that any Apple apps I already own, such as Pages and Numbers, carry an "installed" banner instead of a price. This doesn't seem to be the case with non-Apple apps (such as OmniFocus) where I could inadvertently purchase again.
As I said yesterday, the new Mac App Store is bound to encourage a steep rise in sales of Mac applications. I bet the tills are already ringing full time at Cupertino. It will be interesting to see how stock numbers rise from the current 1,000 and whether the growth will be any where near as dramatic as it was in the early days of the iOS App Store.