I think it's a big issue at club and county level. I have no problems with young overseas players qualifying for england through county cricket with the intention of playing for england (if selected) but I don't see the point in second rate, over the hill kolpaks or overseas players. T20 this year has brought some very good players in - Ross Taylor, McCullum to name two, but county cricket won't improve by playing Collymore.
On the club front, it's more the drain of club funds that gets me. I've seen clubs almost go to the wall in the pursuit of bringing in an overseas. Most do make a difference and many do help develop the colts and the club with their knowledge. However, cricket clubs are run by amateurs, paid for by amateurs and any profit ought to be directed into better facilities and youth development. If we banned payment of players then clubs could get on with developing talent and investing money into bringing players into clubs, surely a better idea. Would also be handy if overseas players didn't get use to english conditions before they played for their countries...