In proceedings, papers are printed in a hard-to-read two column format and are artificially cut off at (usually) 10 pages. Personally, I look for a more readable/extended format on-line before suffering through the conference format. However, if we no longer have printed proceeding (or even if we did, but also had on-line proceedings) then these restrictions would no longer need to apply. We could print things is a way that would be much easy to read and could have original versions of the papers that we not oddly missing some proofs or sections.We have the two-column format in proceedings because it saves space, a paper typically drops 30-40% by moving to a two-column format. Less white space.
Is this a good idea? Why don't we start doing this now?
But I would go further than Grant and suggest that every author should have a complete version of their paper available on their web pages and/or an archive site before the conference. I hate the phrase "A full proof will be available in the full paper" when one doesn't exist. But I don't want to require the extra version or we may end up discouraging people from writing up their results properly with yet another deadline.