We won't "evolve" in the traditional Darwin sense. That stagnented after the most recent ice age. In fact, humans probably haven't evolved much at all since the Native Americans/Aborigonies landed and setlled in their respective territories. BUT, we will still make our selves stronger and more adept as a race. This will happen with genetic engineering. Of course, first, it will be the rich that adopt this. They will create a class of super humans. Ultra good looking, super healthy, super strength, free of genetic defects, a higher predisposition to gaining "intelligence," etc. As the needs for humans on earth changes, so to can the genetic treatments be altered.
The poor will adopt this practice once it becomes cheaper/common. The rich may try to keep this from happening, as they need SOMEONE to rule over. But, this may be prevented with inter-class relations and all. For a few years expect a few reality shows like "Who wants to win a Designer Baby!?"
This genetic altering will be a major thing for a few generations, much like polio vaccination. Once all the genetic "impurities" are weeded out only minor checkups will be needed to correct minor genetic alterations, deviations, and or mutations that may occur. Get ready for everyone and their cousin to be "hot." Also, percautions will be taken to make sure that the alterations make up for the shit we did to our enviroment (e.g. naturally tan skin to combat the harmful rays of the sun to make up for the hole in the ozone layer)
This is our form of evolution. Our brains, our intellect has allowed this to become reality. So I guess Lamarkian theory was just a prediction to our future as a species... Sick, sad, but that's the way I fear it's going to be. Luckly, I will only be around to see the genisis of this practice. The horror.