No, since then Google opened up Google Compute Engine for everyone. I'd consider AWS and GCE roughly comparable; I'm kind of tempted to run them head to head (vs. a baseline of a real server in a colo) and do perf/reliability/etc. testing.
AWS networking continues to kind of suck; Google probably does at least that part better.
I wouldn't say AWS is the only option, probably just the most popular one.
Other options might be Rackspace, Windows Azure (I think you can run Linux VMs, however I dont know how well that's working) or Google Compute Engine (rather new, so YMMV). Those are probably the biggest players in the cloud market.
Digital Ocean still has a lot to prove, but in my testing, they have comparable stability, and disk, CPU, and memory are all faster. I'm not going to start recommending them or putting anything mission critical there yet, but they're the closest thing to Linode, in my mind, in terms of 1:1 setup and management.
That depends if they can now live-migrate cloud servers from one physical host to another. We got burned because to do maintenance on the host they had to take down all 'cloud' servers, turn the server off, do it and switch it back on - and this was planned maintenance, not emergency.
This was before OpenStack, but trying to get information out of Rackspace about what's changed is like trying to get a Republican to vote Democrat.