"Beware the Single Vendor as Trusted Advisor: Gartner". So read my blog of Oct 22 2007.
What's changed? Not much. Cisco is still reaping huge margins in its data business at the expense of its customers, who are also hit with higher energy bills.
Cisco's launched Energywise, but that hasn't made Cisco switches any more efficient, and just locks the customer further in.
So what's the prognosis?
There is lots of talk about who might be looking at Nortel Enterprise and different scenarios of how Nortel may re-emerge after creditor protection. Hopefully, whatever happens, in the end, enterprises will have a bigger choice in how they build their data networks.
Anything is better for enterprises than one dominant vendor.