They all get what they deserve
If the Whiptail buy hurts either NetApp or EMC, they get what they deserve. NetApp for resting on its laurels and generally naffing around for the best part of 10 years with Clustered ONTAP, while the world moved on. EMC for bringing out the bag of spanners that is XtremIO to make, when it is frankly, just not a good story; sadly though a story that many EMC customers will ultimately find out for themselves due to their Xtreme marketing.
One view, is that this would hurt the vBlock alliance more, as you actually can buy the vBlock as a complete bundle. For people looking to stick some basic VDI services together the Whiptail stuff will fill in the storage piece and mean they don't need to go to VCE. For NetApp, FlexPod is a channel-friendly blueprint that partners can do to market with around converged Infrastructure. You don't buy it as such from NetApp and partners often wrap for services etc. around it, which fits the NetApp unified and backup story better if you need a complete solution. It gives gaps for partners to add other services and value. Just one view though.
Anecdotally on Whiptail have not heard good things about it reliability or efficiency wise, but be interesting to see a real customers view on that. $450m is still small beer for Cisco, and every storage play in town wants to be cozy with them. There seems to be a bit of a Nimble bromance going on as well. Cisco can also afford to be Switzerland here as anyone with 10GbE or FC can play in the UCS stack and call it a Validated Architecture. It all drives UCS/Nexus sales - do they really have to care?