Hello All, Courtney Leigh here. I have one true, reoccurring thought about blending genres: it's probable. Same goes for genre-hacking (or as others would say, genre hopping). I think 'hacking' just gives 'hopping' an edge.
Most of my friends and fellow authors don't just read one genre. I'm guilty of reading Jodi Thomas historicals, Amanda Quick regencies, Stephenie Meyer paranormals, and Nora Roberts contemporaries. So why SHOULDN'T I think of writing what I love to read? A lot of other people/authors are like me--their preferences are eclectic.
It only makes sense that their writing would be eclectic, too. Soooo... it's probable, the concept of an author wanting to write more than one genre. But it's also important for authors to keep their mission statements handy--and not lose sight of the prize by becoming overstretched. After all, a Jack of all trades is a master of none.
Some authors have created different pen names that are genre-specific. Some can get away using the same name in multiple genres. Stephen King is the perfect example, as his horror and his paranormals and his other work all have one name on them. Stephen King. (Keep in mind, when King started out he stuck with publishing horror. Once he became huge, he diversified his portfolio.)
Jayne Ann Krentz (aka Jayne Castle, aka Amanda Quick), explores several different genres simultaneously. (Also keep in mind, these pen names were created out of necessity through the years as a way to keep her career varied and regenerative.)
All in all, I honestly believe breaking into the publishing industry in one genre is the first step. Once you've established yourself as a master of one...well, diversify all you want!