I know what you meant, but I think it's helpful to talk about "trendy" in the context that matters: something popular that will either widen the competitive moat for existing customers, or bring in new customers that are soon to graduate into wanting enterprise support from a VMWare or a Microsoft.

VMWare is an interesting possibility! Docker seems like it would cannibalize too much of their existing product line, but VMWare's existing products are already kind of self-cannibalizing. (This is why many engineers find the enterprise market so confusing. Nobody differentiates products well, because past a certain size, networks of human relationships [sales, support, etc.] matter more than branding.)

But from that "good for us" perspective, VMWare looks as bad as Oracle these days. I would still "vote" for Microsoft.

Docker would fit nicely Microsoft’s Azure container offensive and new found love for all things Linux. They tried Mesosphere, but that didn’t work out.

Can you elaborate about what has been tried and what hasn't worked out?

Microsoft made an offer for Mesosphere, but they turned it down [0]. These deals are of course never that "snappy". They probably had long and hard negotiations, but the deal never happened.

0: http://www.businessinsider.com/florian-leibert-mesosphere-ce...