But from what you say...
Or have humans reached as far as evolution can take us?
it sounds like you may be misunderstanding some of the concepts of evolution.
badly phrased, perhaps, but i think you're missing a certain concept. a creature that fits its niche nearly perfectly can essentially cease to evolve. although genetic drift does occur of course, major changes are less advantagous than pre-existing adaptation. basically, it's like natural selection keeps the animal from really going anywhere until some kind of environmental change happens.
this is the reason we have things like the great white shark, which hasn't had any major change in about 65 million years, when it became drastically smaller.
humans are good creatures in that we fit our niche -- even through changes -- very well. we rely not on evolution to adapt us, but technology. we may have even overridden certain aspects of natural selection with the development of modern medicine and antibiotics. if we were to have an ice age, we'd cope quite well. not by evolving into a more neanderthal shape, but by making coats, heaters, etc.
have we stopped evolving? well, not really, because genetic drift and other mechanisms still happen. but i think it's a very real possibility that we've slowed it down, and even "devolved" in some respects by developing dependencies on certain technologies.