With the way the Switch button now works, this would be feasible if enTourage wanted to implement it. Certainly easier than popping up the Reader app from the LCD to pick from the Recent list.

However, since the eDGe remembers what page you were on, and at what zoom level, the Recent list is a workable solution, just slightly more inconvenient.

But, if you have more than one book open, you'll have to cycle between them to find the one you want, which will probably get to be a nuisance (especially if you accidently pass the one you wanted and have to cycle through all of them again). You'll probably find the Recent list on the LCD side much faster to jump to the book you want right away, and with the larger Recent List dialog now, you can have 7-10 books at hand.