On the one hand, I completely agree that paring pounds off your pack is a great thing. And it聮s not hard to do聴with just a little effort, today聮s lightweight gear makes it possible to shave 10 to 15 pounds off a basic load (tent, sleeping bag, stove, etc.). And if you聮re diligent, you can peel off even more.
Gregory Z55 backpack

But, I聮d suggest you start with the load itself, then work down to lighter footwear. I聮m not a proponent of trail-runners-as-hiking-boots in the first place (not enough support or foot protection), and that goes double when you聮re carrying a big load. So make your pack lighter before switching out boots.
Where to start? You can make pretty big gains by swapping out your tent, sleeping bag, and pack. 聮s new Zonda 2P tent ($289), for instance, sleeps two and weighs just under four pounds, two or three pounds less than two-person tents of even five years ago. 聮s U.L.SS Down Hugger 4 sleeping bag ($255) is good to 35 degrees and weighs a feathery one pound, five ounces. 聮s Z55 pack ($199) can handle today聮s lighter loads for trips of four or five days; it weighs just three pounds, five ounces. So between those three items, you cut the load by probably seven or eight pounds compared with similar stuff from several years back.
Once you聮ve done that and trimmed your clothes-load a little (聮s $199 Taku Jacket weighs about half what rainwear used to), then take a look at your feet. But I聮d go with a light boot, not a trail runner. 聮s FSN 95 GTX boots ($170) have the feel of a trail runner but the good support of a boot, plus they have a Gore-Tex liner. Or, there聮s 聮s Onix boots ($135), which are more of a mid-height to suit your craving for light footwear. But they can handle trails and moderate loads, so as long as your ankles are in good shape, you聮ll be fine!
The 2008 Summer 国产吃瓜黑料 Buyer聮s Guide is now on newsstands. Look for it online soon.