[caf]

That's not the feeling you get when you use it, it seems more like the underlying engine hasn't really changed a great deal in 20 years.

[smitherfield]

That's the price of backward compatibility. But I think it's a bit of a "Seinfeld is unfunny"[1] situation; if Microsoft decided to save on the nine-figure budget and outsource Excel development to, say, your favorite purveyor of antivirus software, you'd notice real fast.

[1] http://tvtropes.org/pmwiki/pmwiki.php/Main/SeinfeldIsUnfunny (apologies for the TVTropes link at night!)