With all due respect to Aaron, and as someone who wants enterprise software to get the attention it deserves, this reads more like an ad for box.net than a compelling argument as to why enterprise is making a comeback. Of the few investments being made these days, venture capitalists are by and large investing in consumer products and "green" technology, and until they feel those markets are totally saturated I don't expect much will change.
It's also the rare twenty-something founder straight out of college in the Valley who knows anything about double-entry general ledger systems or what CIOs of Fortune 500 companies really spend time worrying about. When I see headlines about Oracle and SAP worrying about their profits, I'll be more convinced that something has changed.