The Y410 is intended more for individual general purpose use while the Thinkpad line is targeted more toward professional usage. Both systems should be able to handle general purpose computing.
You may also note that the new Y510 and Y710 models were just announced and should begin appearing in stores soon. I believe the Y510 will be available slightly sooner.
You can compare features online between these systems and decide if one is right for you. You might also keep your eye on the new IdeaPad section of this forum, and as the first customers get systems, I hope they will share their thoughts, and this may also help you in your considerations.