Use a smart os, use trim, right fs/mount options, ram temp folders etc and you'll be fine for many years. But sure, if you benchmark your ssd everyday you'll wear it out a bit faster than it would during normal use.
normal usage - where you are constantly at 80%? trim - that not even implemented command?
ssds might be ok in some years. but I am not holding my breath.
TRIM is supported in Windows 7 and Linux (ext4), the next FW (coming this week) from OCZ will support it.
I don't consider constantly at 80% being normal usage, but I get your point. Actually my Vista partition on my Vertex has been sitting on 9GB free of 46GB for a while now, and I haven't experienced any slowdowns.
I got the SSD because I wanted superior performance for a good price. In a year or so there'll be a lot faster SSDs with greater storage for the same price, or you could get the original Vertex for a few dollars. Everything has shortcomings, if you want the best you will constantly upgrade.