We're living in an era when it is easy to create new "currencies". Bitcoin is only the first, as some others have already been developed. The "value" of such currencies is a social construct. So, the price of BC will continue to grow as long as people have expectation that it will be valuable in the future.

The only problem I see in "investing" in BC is the counterpart risk, i.e., I don't trust any of the companies that do trading in BC. I think this problem is currently bigger than the "currency" itself.