The major change is that now there's an additional xs module you can install called Algorithm::MarkovChain::GHash. This interfaces to glib in order to use less memory. I've got further modules that will use MLDBM and DBI as backends, but they're currently in a state of flux as I changed an interface mid-hack.
It feels quite odd, it's the first proper coding I've done in almost a week, and on code I've really not touched in almost a year. The strangest part was in figuring out how to successfully test it, as the module outputs statistically consistent random gibberish. I'm glad that I did at least some testing though, as I had a few lurking segfaults in the XS code it flushed out.
I'm still waiting for someone to lynch me for Devel::LexAlias. Nick Clark pointed out there was a thread on perl6-language about using the perl6 %MY hash to do lexical aliasing at a distance badness, something which Devel::LexAlias already lets you do in perl5
Wait until perl6 to do insane things? But where would be the fun in that...