Well, there are some dates that are fixed either by plans or by physics and technology (arrival and EOM dates for interplanetary probes).
For example, 2011 is sure to be the shuttle retirement date; 2011-2012 will be the completion of the ISS. ISS is likely to be deorbited in 2020 or maybe 2025, and circa 2015 at the worst.
Once USOS operations stop, there will no longer be an ISS. Russia will likely continue operating a space station of some sort, as will ESA, potentially in a joint program (see ATV-derived Mini station, etc).
We'll see Dragon flying to the ISS first and if all goes well it'll give the US more-or-less reliable access to LEO. Once the ISS reaches the end of its life there won't really be anywhere to go to for a US program, considering the spacecraft themselves can't really be used for much on their own, so some sort of US station program (or cooperation with Russian and/or ESA efforts) is possible.
China is progressing at a snails pace, they have a painfully low flight-rate. They'll get around to launching their space station- slowly. They're definitely not going to get to the Moon by 2020, or even 2030, unless they accelerate to Apollo-like levels of progress. I doubt anything would motivate them to do so.
India also has plans for a manned capsule and a Moon mission in the 2020s, but that won't happen; they haven't even flown their capsule yet and Moon vehicles are unclear. Maybe they too will progress, however.
We might see a ESA-Russian or a US Moon program within the next 40 years, with infrastructure and experience built up over multiple years in LEO. There are reasons which would make it likely and reasons which would make it unlikely. It could end up being very much like a sort of 'budget Apollo', doable, but not really leading to anything more.
I severely doubt we will see a Mars landing within the next 100 years or more, unless there is some sort of wild-card that catalyses such a program (and the thing about wildcards is that you can't predict what they'll be or when or where they'll pop up). Or unless the cost of such a program and the hardware involved drops enough to make it viable enough for politicians, but that is unlikely.
We might see, as technological proficiency increases, a slowly dropping cost/kg to LEO. If Skylon is researched enough, built, and does what it says it can do, it could potentially be very disruptive to the launch market and potentially put most conventional launchers out of business. If. If it is successful enough (read: better than STS about delivering on its promises) it might see adoption with ESA or others depending on climate, cost, and motivation. If doesn't fulfill its promises at all (pretty much like STS), then it'll further bitter attitudes and experience towards spaceplanes/RLVs.
But it is unlikely that cost/kg to LEO will magically drop to tiny levels, certainly not within the next 100 years.
Virgin Galactic will eventually start flying commercial trips on SS2, which could be a profitable endeavour; over time, operation of such a vehicle could become cheaper and safer. But a suborbital vehicle is nowhere near on the level of an orbital vehicle, and it is doubtful that purely commercially-funded vehicles will arise to fill the need for space tourism. But we could see more tourists on Soyuz, to varying degrees, and potentially on Dragon or a similar US vehicle, eventually. But it's doubtful that there will be huge space hotels, or even small space hotels; tourism will likely be erratic, piggybacked onto missions with other goals, and be only for the seriously wealthy (in the order of several million USD per seat at the least).
Mark my words: there is no advantage to BEO manned spaceflight, and for cost, little advantage even to LEO manned spaceflight. There is no reason to go to the Moon, or Mars, or even LEO. Nobody cares. It's space; most people don't even fully grasp that it's a real place. There are no advantages worth the cost. We can go on about interplanetary lebensraum, and space survival, and deflecting asteroids and whatnot, but the cold hard fact is that nobody is going to care about it; at least not in our era. Science doesn't cut it. We- the space enthusiasts might want to see these sorts of scientific discoveries, but most people, politicians, they don't care. They don't give a damn about the ice content of Hyperion or the composition of the rings of Jupiter. It means nothing; a nice little bit of trivia, from a place so far away from our troubled little world. Not useful, or helpful, and at a cost as well. Why should we do it?
I know that's a very pessimistic point of view. But in my experience, all I've seen from spaceflight is failure, capability devolution, exorbitant costs, exploitation by politicians, corruption, unimportance, and downright disinterest from most people.
I wish we could do more in space; I wish we could finally grow up and take a challenge. I wish we could actually do things. I wish we could settle other worlds and send missions to the stars. Heck, I wish I could go to those places out in space myself.
But if we don't have a reason, if we don't have a proper attitude, our chance of doing anything new in space in the next 100 years is about as high as me staging a superluminal trip to 55 Cancri from my backyard.
If we don't have a proper attitude, we might never do anything interesting in space.
Might be nice to have some debate about some positive imaginationy dreamy stuff for once!
