1- It will make both parties even more divided
2- It will strengthen the current government (as being under attack)
3- It will push more and more towards the idea that an international tribunal is necessary
4- It will create restraint in the ranks of Hizbullah and Tayyar
5- It will alienate another segment of the Christian population to pull out of Tayyar
6- It can reinforce the specter of federalism
7- It can keep Israel out of the picture for a while
In general, think of any assassination in Lebanon (and elsewhere for that matter) in terms of how much division it can create, and who profits from these divisions.