As for the advent of 3.0, the best thing for you, most likely, is to do is go with 2.9.2 for now. This is a stable release, two versions after the initial 2.9 release. Much of the bugs and security issues of previous versions have been worked out, and (on most hosts) it works very well.
3.0 is a landmark release, promising many new features. While it is good to have more features, none of them have gone through the test of being used by ordinary WP users. There will be bugs and changes that will come in future minor releases.
I believe that Forum Moderator Otto42 has more on this on his blog.
If you are a blogger, and not into XTHML and CSS customizing, you can get away entirely with using an existing theme that you like now, and upgrading to a 3.0 theme (which utilizes the new features) later. If you go with a reputable theme with a large user community, the author may even update the theme you choose now with the new features. If, however, you do customize your theme, you may have to reinsert your customizations with the new theme.
On the other hand, the advice to stay with 2.9.2 is mostly directed towards users who already have well-established sites, and might be more inconvenienced by the bugs.
Sorry for the long explanation, I will summarize myself quickly:
- If you want all the new features of 3.0, and are not worried much about potential bugs, by all means go with it! You will have the added benefit of a single install. (until the next, more stable, version comes out…)
- If you want to start with the proven, solid release of 2.9.2, and not be bothered with excessive bugs, then you are better off with the current version. Then, you can wait until after the initial 3.0 release, and go with the 3.0.1 release (which will probably follow it very quickly), granting you more stability.
By the way, upgrading is actually TONS easier than the initial install. Most of the time, the install script will work perfectly and you will make a seamless transition. Backups are still recommended, because errors happen.
In the grand scheme of things, choosing either way will work. Make your choice, and have fun blogging! Check back to the Forums or the Codex with any questions you have, and 90% of the time you will be fine.
Good Luck,
MindBlender 3D