Speaking of moon colonies, I believe Japan is already working on plans to construct a facility there to mine helium-3, which is a fusion by-product that... aw hell, if you want to learn about it you can wiki it. Suffice to say it's a tremendous source of power and if it can be mined and transferred safely then it could solve a lot of problems on Earth. I'm actually doing a literature review at uni right now on methods for using bacteria to generate hydrogen from sewage- there's some amazing work going on right now on enzymes, photocatalysis, nanotech and customised life-forms coming down the pipe (sometimes literally) that could well revolutionise the energy industry in the coming decades.
If we can restrain the supervillain-esque urges of Monsanto and their ilk we may be able to turn genetic modification of food crops into something that can keep everybody alive and healthy while we sort out our population issues. According to David Attenborough (who got his information from reliable anthropologists) the best ways to reduce the number of children a couple have are:
1) Reduce poverty- if you have more cash you don't need as many kids to support you in old age
2) Provide education for girls, encouraging them to find work and marry later (if at all)
3) Barrier contraceptives, baby (no pun intended)
It's going to require some big changes in attitude, but it can be done. It'll have to be done.
On the more techy side of things, we're fast approaching the technological singularity- in the next 5-10 years artificial intelligence will supercede natural intelligence and we may find that our creations and their truly "outsider" perspectives will help us to take a better look at ourselves. Sharing the planet with something smarter than us might inject some much needed humility into our assorted leaders and CEOs. Or it'll be war against the machines, but peace would be so much more interesting
On a personal level... I dunno. Cranial implants? Babelfish 2.0 installed in children to let them understand and (sort of) speak all languages? Brain mods to make us hyper-intelligent? The internet 3.0 and beyond redefining the concepts of 'intelligence' and 'education' to reflect the limitless knowledge available online to anyone who knows how to find it? If the internet has taught us anything, it's that whatever's coming will be moe amazing and more bizarre than anything we've come up with so far.
And, of course, we'll all be old duffers by then and whatever the future does bring we'll look upon it with disdain and tell our grandkids that it was so much better in our day when if you wanted to beat a virtual hooker to death you had to at least pick up a controller...
-Nick