Marcus,
One of the things you should know realize about many of the demo reels you see in the demo forum is that those are compositors and motion graphics people who just do that type of work. So really you are comparing apples to oranges if that’s not what you do full-time.
As to the initial query, house I work at does 90% corporate video. Of that, we probably need to use AE for compositing, effects, animating logos in about 60% of the video. If you pick up the AE and the first Trish & Chris Meyer book, Creating Motion Graphics in AE, you will probably be able to handle 95% of your clients needs in regards to that little extra polish for corporate video.
If you check out our site which has quite a few vids up in the gallery, you can get an idea of the effects composition that corporate clients require. Just a warning, most of them videos are of the most visually interesting parts, after the first 20 seconds or so we start showing products or talking heads.
Johnny Cuevas
Editor
CK&Co
http://www.ckandco.net