We did this at Nykredit (a mid-size danish bank) 1½ yr ago. The two major problems we had (still have!) is CPU clock-speed and number of I/O channels to the external diskarray (a SAN I suppose).
We are using two IBM servers, each having 24 1.87GHz cores, 1 TB Ram and 1TB internal SSD for workspace and like. Only running classic SAS and EG on top of that.

Looking back I would trade number of cores for a higher clock-frequency and more I/O channels. And I would go more into the capabilities on the external diskarray, actually I would prefer a high-performance DAS to SAN. But it depends on your IT- and BI-strategy (and the size of your wallet), and who's "running" your server (your company or someone else).

All in all we see a consolidation as at great advantage as it much easier to manage your SAS eviroment this way.