I certainly think it is a good thing.
What does concern me though is how the pricing pans out. I'm hoping it
doesn't become a race to the bottom, with apps having only a few
features and charging small amounts for it.
Though, if there is a general price drop, I do suspect that will more
than likely be able to be made up in the extra number of sales, I
think it was Ars Technica who said something along the lines of
"whilst Apple will be taking their 30% cut, 5 sales with 30% of the
revenue is better than 1 sale at 100%." So, at least with that in mind
I do suspect it will work out.
But, as the OP says, will the sales boosts last? Indeed, it has worked
for the iOS App Store, but to discover the best of the applications we
still find out through what is essentially word of mouth. These days,
that is generally high profile bloggers, from Gruber to Shawn Blanc
being good examples of that.
Of course, the very fact we're on this list makes us technically
competent users, so this isn't the market the Mac App Store is
attempting to fill. I certainly think it will overall increase app
sales, as more people discover the other great software that is out
there.
Nick.