I was vacillating over this and now I have enough evidence to decide and the answer is...
Absolutely! Do It!
It works like a dream, though after having been programmed to respond to email in a Pavlovian manner for quite some time it is pretty scarey coming into the office in the morning and ignoring whether there is any email.
Having said that the ability to plan first thing in the morning is one of the most liberating things that I have yet to experience in my working practices and takes me back to the days before email became prevalent and when that was what I actually did!