Hopefully, current "rich" BTC holders have considered investing in BTC infrastructure/business ventures using their BTC? I would think people would work and get BTC as payment - the "workers" or partners, whatever you would call it would basically be investing their time in BTC and the product, with the hope that BTC becomes more widespread.
If I had say, 100K BTC right now, I would be looking at partnering with finance people, software developers, etc - offering them some of my BTC + share in future profits in exchange for creating something. Like a GOOD exchange (something like PayPal with BTC support, where I can link my bank account and just start using BTC), or a secure bank, or an insurance service, etc.
It wouldnt even have to be infrastructure, supply of high demand services or goods would be just as important, but would at least need a good exchange first.. For example - betco.in is a good poker site for what it is, but it is pretty lame compared to the good software that is out there (PokerStars, Full Tilt, etc) But what if someone were able to go to say, Tilt Ware, Prima or Merge and work out a license agreement in BTC, to run a service using their software denominated in BTC?
I have just read a few threads of people just sitting on tens/hundreds of thousands of BTC and doing nothing with them - they could possibly be worth much more if those people would help get this really rolling - and not some rinky dink 1-2 man operation (Mt Gox, etc), but a real investment in high quality infrastructure that the masses of "normal" people would be interested in using.