UPDATE (1/24/12): Google has made changes to its search algorithms that have caused us to change our position on Google+. For more recent information, please see our newer post: Google Wants You to Plus.
YES, it is too early to effectively use Google+ for social media marketing. Put very simply, Google+ is too young of a technology and hasn’t developed any tools that would make it genuinely useful for companies. If you want to use it for personal networking purposes or just to get a feel for it, then sure, create a Google+ account but your Google+ account has to reflect YOU (literally – Google doesn’t allow corporate accounts yet). There is also a very high likelihood that you’ll have to attempt to recreate all of your connections if something akin to a facebook “page” is developed for non-personal uses.
When Google+ begins to allow corporate accounts and / or develops other tools that allow companies to leverage it effectively, that’s the time you want to jump in. Until then, it simply won’t provide anywhere near a desirable ROI and there are no benefits to attempting to be an extreme early adopter (or “innovator”, as the technology adoption lifecycle would call them).