There was a similar case recently about a man who got in trouble for hugging a police officer. Cases like these seem so trivial, and I agree that with the state of our world today, we have better things to worry about than offensive actions committed against police officers. What does concern me about it is the precedent it sets.
Police interface with people constantly and I'm sure there is often tension between them, especially when dealing with people who are wasted enough to get so up close and personal with them. There's a delicate balance between discouraging people who would abuse and attack them (even with things like spitting and passing gas on them) and giving the police too much control (leading to them abusing their power). I do agree that battery is going way too far, no matter how offensive and pungent the crime may be.
I think this kind of crime is perfect for the I Was Stupid Sign punishment.
Every man dies, but few truly live. Live your life to its fullest, every day as if it were your last.