I've been thinking this myself. On one hand, now is certainly the time to get in if Steem IS a good investment, and the platform is certainly a good design. It's attractive to both content creators and users, and so it kind of does the Reddit thing but with financial incentive. And people love Reddit even WITHOUT financial incentive.
On the other hand, just because something is good doesn't mean it's going to work out. The issue is, Reddit already exists and is massive, and the more people who join Steemit, the harder it will be to make money from it. Which is why I think it may not work.
Fingers crossed though as it is a good system!