In practice I think PP has a long way to go before it is truly usable by most people..
Heh...I'd argue it's the other way around. Most people have a long way to go before they are able to use PP. Hell, most of the analysts I work with don't know enough about Pivot Tables or even Excel Tables, never mind PP ;-)
My point above about PivotTables being the "best" thing about Excel certainly
is a matter of opinion. And PP certainly lets you mash up more data from more places, using more languages than we had access to before. And that's not to be underrated. But PowerPivot is quite a step up from PivotTables, and PivotTables are quite a step up from doing analysis
without PivotTables. So I'm happy to opine that Pivottables are the best thing about Excel in the context of this particular forum post. In another forum post - in another question context - I'd say that VBA was the best thing about Excel. But for this poster, I think looking into Pivot Tables might well be the best addition to their Excel toolset for their money. I certainly wouldn't be pointing them to PowerPivot...even though PowerPivot is to PivotTables what the rocket engine is to the wheel.
Pivottables are like the gateway drug of higher data analysis. Lets think about what a Pivot Table does: it allows allow intermediate users who have little or no understanding of formulas or SQL to filter, summarize, and slice like an SQL pro and/or formula Jedi. And it allows it right out of the box using pretty much drag and drop. No advanced SQL neccessary, and - like with a car - you only need to know where to input the gas. No understanding of the underlying mechanics required.
I've seen a lot of interesting posts on quite tricky problems answered with some very tricky formulas that the user probably could not have come up with on their own even given their current understanding of formulas. And for
some of those problems, I've noticed that a pivot would allow pretty much the same thing; but the difference being that the user
could easily grasp the basics in a matter of hours or days, rather than the months or years to get up to a similar output-enabling level using formulas.