WordPress 2.8 offers several improvements, a few changes, and nothing that needs to worry you.  From what I’ve seen at my websites — on two different hosting services — WordPress 2.8 is fine.

Your Appearance > Editor screen will look a little different.  It includes line numbers on the left.  That can make it easier to go back and tweak a line, without having to scan code to find it.

Also, if you add an “a href” link in your Editor screen, the program adds the opening and closing quotation marks automatically.

Some plugins may not be updated for 2.8 yet.  If you have any problems with them, you can either Deactivate them (in Plugins, on your WP dashboard) or delete them via FTP.  (I did the latter for the Limit Login Attempts plugin, if it locked me out.  But, that only happened on a few sites.)

So, go ahead and update to WordPress 2.8.

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Also, here’s what I said when WordPress 2.7.1 launched:

If you’ve worried about updating from WordPress 2.7 to WordPress 2.7.1, you can relax.

In general, the changes in 2.7.1 are behind-the-scenes and affect minor code issues.  The biggest change you may notice is that most plugins work again, now.  (Chances are, you didn’t have a problem with your plugins, so you won’t even notice this.)

Your dashboard will look the same as before.  Everything should work the same or better.

So, it’s safe to upgrade to WordPress 2.7.1 if you were using WordPress 2.7.

(If you hadn’t upgraded to WordPress 2.7 yet, the new dashboard looks very different.  If you upgrade to 2.7 and you’re very confused about the changes, the new edition of my book covers the biggest changes.)

On my websites, I’ve upgraded to WordPress 2.7.1, and I can’t see any differences between that and WordPress 2.7.  Life is good!