Yeah, there was talk of some experimentation by CZ into 10mm territory a few years back, including demo or two, as others have pointed out, but I'm not holding my breath on it.
Besides, if you want a Bren Ten, I recommend checking out the Tanfoglio Witness Elite series in 10mm. I'm currently saving up for one of these myself.
Of course, Grand Power just released a "long slide" version of their P40 in .40 cal and 10mm, and is selling for less than the more upscale versions of the Tanfoglio. I might consider one of those, if and only if I can find someone who can get some parts for it and do a bit of custom work...
But for now, the Tanfoglio model I'm saving up for is the Witness Elite Stock I. It pretty much nails that Dornhaus & Dixon Bren Ten aesthetic, and has a nice, stout cone-lock barrel, to boot.