|No software can do the exact same things another software can.
And you can't even compare Blender and After Effects. AE is a 2.5D tool, while blender is mainly 3d. Blender has more with Autodesk Maya, 3ds max and Cinema 4D in common.
AfterEffects is great for compositing and effects, but they are rather 2d based. You can't create complex 3d content with it, for that, you can use Blender.
Latest Blender, 2.64, has many features like AE, e.g. Masking with adjustable feather for video clips, 3d tracking and so on. However, workflow, performance and quality differ a lot. If you can't afford AE, go try out Blender, but if you wanna do compositing, video cutting etc., i would recommend AE as it's the easier-to-learn software imo.