I found David Merrill's blog entry here on Squeezing (Easily) into Tight Jeans amusing. David is talking about a couple of his customers who were using various capabilities to reduce the amount of storage they needed; I suspect using techniques such as thin-provisioning and the ability of the USP-V to consolidate islands of storage into a usable pool of storage.
And then they were going to decommission a whole bunch of arrays and reduce the amount of storage on the floor. I think David was surprised that they were choosing to decommission the storage as opposed to simply use the reclaimed storage for growth.
But sitting on this side of the fence, the customer side; this is no big surprise at all. Depending on the age of the arrays and depending on the software sitting on the arrays and especially if the arrays were out of warranty periods; the maintenance costs are generally so high that it simply does not make economic sense to keep them around.
Software maintenance on all of the Enterprise class arrays is just plain expensive. If you then factor in that if you are trying to sweat an asset for a couple of extra years; that is another couple of years of what are often power and space inefficient arrays and you are going to be looking at another migration effort in fairly short order, it does not make a huge amount of sense.
The situation is actually a lot less clear on mid-range arrays as the maintenance costs are often considerably lower but if you have got aging Enterprise arrays; get them out if you can.