So whats the question?
Honestly, I am not very clear of your question but here are my 2 cents.
I have all of the gadgets you mentioned and use it regularly.
e-book reader, solely for reading epubs. My actual idea was I could read scientific research articles on it but it doesn't work well so I read ebooks on porcelain throne and on the train to work.
Tablet (Motorola Xoom), primarily used for reading scientific articles using iAnnotatePDF app (yes, their android version is free, grab it ASAP). When home or when I am absolutely tired/bored, it is used for playing some games. And of course, the other regular stuff like RSS feeds, emails and regular early morning coffee stuff.
Laptop is used primarily when I have loads to type or the stuff that I can not do on the tablet.
I believe, you can very well replace laptop with the tablet for college work and even for making notes during the classes, if you pay up for decent apps.