Apple’s Mac App Store opened its virtual doors today, and if it’s like any other Apple Store opening, hordes of fans will have flooded it to shop.

But is this an idea that’s going to take-off like the iPhone or sink like the Newton?

The store interface itself is as slick as anything designed by Apple, with much in common with the iPad App Store. One of the nicest features is the tabs along the top. While three offer ways to find and buy apps — featured, top charts and categories — the other two allow one click access to previous purchases and updates, which seems a handy organisational tool.

Annoyingly, you’ll need to upgrade to Snow Leopard if you haven’t already. And, you seem to need to verify payment before downloading, even for free apps (or at least I did, which might be because I’m using a different computer than normal). Once that’s sorted, clicking the “free” button or the item’s price kicks off the download. Be careful once you’re logged in with a valid credit card, though, as all it takes is one misplaced click to accidentally buy an app, which is how I came to own a copy of Courier.

Downloads take mere seconds, with a nice animated swoop sending your new software to the dock.

Unsurprisingly then, it looks good and is lovely to use. But is this really the way people will choose to buy software in the future?

Software choices

I wonder because many of the most popular downloads so far today are mind-boggling: StuffIt Expander, Pages, Twitter… even Solitaire. Were the Mac masses desperately awaiting an Apple-approved app to buy such apps? Because these seem like the sort of software you’d already have if you wanted it, given they’re all widely available online.

While a fair number of the 1,000-launch apps are for the Mac App Store only, much of the most downloaded software have long been available online for Macs, simply by heading to the developer’s website.

For example, Evernote is now available free on the Mac App Store. However, it’s long been free for Macs via the web. It’s hard to believe anyone choosing to use the notetaking software never found it appealing before today, but faced with a clean-and-easy interface instantly had the desire to download it. Maybe this is some weird launch day anomaly, where users download like mad just because they can (I did the same thing after my Kindle arrived, after all).

As our laptops editor Sasha Muller put it: “It’s like Steam. You buy things because you can, not because you need them.”

Either way, it’s proving to be a good move for Apple, with its own software making up over half of the top 12 grossing apps at the time of writing.

Its Aperture photo-editing package even managed to knock Angry Birds from the top spot. That software alone is worth upgrading to Snow Leopard to get your ticket in the door of the Mac App Store, as the photo editing software is normally priced at £173, but has been slashed to a ridiculous £44.99 for those inside Apple’s Snow Leopard walled garden.

There are other rewards to using the Mac App Store. Pages, Numbers and Keynote are £11.99 each, versus £72 for all three on the Apple UK web-based store. And  iMovie, GarageBand and iPhoto are slashed to £8.99 each, from £46 for the package deal online. On top of the savings, there’s the added benefit of being able to pay just for the software you’re going to use. Any Mac user would be wise to upgrade to Snow Leopard just for those savings — it’ll be interesting to watch if installations of the latest OS jump after today.

As iLife comes pre-installed, it’s hard to believe most Mac Book owners don’t have a version of those already, but at least this makes upgrading to the 2011 versions in the store free and easy. On top of all that, there’s another benefit: anything you download can be automatically flipped to another computer if you upgrade to a new Mac, so no more hunting for discs or having to head back to every website just to reload a machine.

So it’s cheaper, easier for some, and can salvage your apps if your Mac Book dies. Considering Google already has its Chrome Marketplace and how unflinchingly we accept mobile apps stores — and even complain when we don’t have access to the best ones — don’t be surprised to see others following the lead of the Mac App Store soon.