The thing that will drive Bitcoin's adoption is the ability to use it in transactions for goods and services. It's still in the very, very early stages, and only pretty serious geeks are using it. The current market cap of the bitcoins in circulation is about $1B, which is a tiny, tiny fraction of the amount of currency in circulation (USD alone is several trillion). Because bitcoin transactions can be executed for next to nothing, I think that they could provide a much more efficient alternative to credit card transactions. If it takes on a larger share of the transaction market, it's value relative to other currencies would continue to grow.
Bitcoin democratizes banking, allowing anyone to pay for things without having to go through a series of intermediary banks and credit card companies. When anyone can have this capability on their desktop, I think that will open up a lot of business opportunities (which I've been exploring for a while). It's still very, very early in the adoption cycle (kind of like the Internet in the '80s), but the underlying technology is brilliant.
As far as Matt's point about mining, I agree with Richard. Mining is really not that important in the larger scheme of Bitcoin. It's a way to distribute the coins initially and it provides a mechanism to incentivize people to strengthen the network. However, the vast majority of Bitcoin users will have no need to be involved in mining.
If anyone is interested in discussing Bitcoin oriented businesses, definitely let me know!