Actually, no.

The GPL and Perl Foundation aren't going to stop anyone from 'Acquiring Perl.' The community can have a limited influence in that they can have a minor boycott of the new language (until their boss says use it, at which point they'll throw their stance out the window, like always). That leaves the artistic license. I don't want to be too critical, but a good license is hard to write. Loopholes can easily be displayed with enough lawyers (and when it comes to holes, the artistic license is to OSLs as swiss is to cheese :(.

So really, if $some_big_company wanted to make Perl its own, it probably wouldn't have much trouble doing so. This is very unlikely though. Perl (<= 5.x) isn't designed as a language major companies would use for large-scale development. In addition, they'd have resources to rewrite it themselves and make modifications as they see fit. Another point to consider is that Perl's an open source language, so they can use it already without charge, they only reason they'd have to acquire it is to sell it to others which wouldn't be a good business decision.

To conclude: they could, but they won't.