I'm under the impression that Denver (and Boulder) already have. The Raleigh/Durham metropolis certainly is, too, because it's not just Raleigh. In fact, although Raleigh is the largest single city, the conglomerate of Raleigh, Durham, Cary, Apex, Chapel Hill, Carrboro (not to mention Knightdale, Zebulon, Garner, and Clayton to the East/South), has been thriving for a looong time. The tech presence has only been growing quickly over the past decade, but Cisco, IBM, Netapp, Microsoft, Google, Citrix, Redhat, Allscripts, and many others all have significant presence there. This doesn't include non-tech tech, like Genband, Gemalto, Cree, and more, or all the biotech/pharma there.
We lived in Cary for 13 years until moving to San Jose two years ago. There are many reasons we miss it.