There are differences in meaning, for me.
"I'll try and get the program done this afternoon" means that the program is much less likely to be finished than "I'll try to get the program done this afternoon." In this case the "to" adds some degree of certainty, while the "and" expresses your doubt that you'll get it done.
Similarly, if you tell someone "Please try and keep your room in order," you're not really expecting them to take your advice, compared to "Please try to keep your room in order." The "to" makes it more command-y.
Try and say those last two sentences out loud. The whole rhythm of the sentences changes, and this affects where the "high point" of tone (and thus meaning) is in each one.
FWIW, I would never write the colloquial "try and" unless I was writing the words of a character who needed to say that specifically.
