HP Storage...
...has already responded to the all-flash arrays with the 3PAR 7450.
IBM's problem is glitz and glamour. Look at how dull and boring the product line is! I've never heard an IBM rep get excited about their products. HP practically froths at the mouth about how the 3PAR stuff is the juggernaut of the storage industry, leaving everything else nothing more than a pile of smoking hardware and red flashing LEDs.
Plus HP positively jumps on any opportunity to do a proof-of-concept and ram the point home (I tend to be very critical of HP evangelists having come from HP before, but the products are sound and that is proven out in the field).
I asked my IBM rep about doing a bake off with a Compellent for me since that's what the very trusted VAR would sell us and he didn't want to participate but I should consider them anyways because of <marketing spew and boring Redbooks>. If the VAR sold HP I guarantee they'd be in like a dirty shirt with their goodies and free lunches and such.
Plus, 3PAR is yellow. Point for HP. If the rest of their equipment was painted to match my server room would look like a bumble bee because yellow means it's awesome.
As for EMC, they own so much of the worlds data (as in, resides on their products) that it is very tough to get people out of the ecosystem. Not that you'd want to as a customer, if you are an EMC shop with existing storage to replace, buying the newest version based on what the SE sizes up for you will certainly not get you fired.
And NetApp is NetApp. Apparently disk is dead and NetApp is so last decade, but it looks like no one got the memo.