My experience is that "noindex" is quite harmless when it comes to ranking. As soon as you change it to "index", the pages should pop up at nearly the same positions in the SERPs as where they were. It is another story when you used also "nofollow". Nofollow alters the flow of pagerank and nofollow can therefore affect rankings of linked-to pages in a negative way.

[edited by: phranque at 1:52 am (utc) on Mar. 16, 2008]
[edit reason] spelling [/edit]

Geez, well I've forgotten to put that on some pages before... not nice at all.. especially since search engines like google are so slow to update there cache, I had to go back and change the pages all around.

But yeah... after you've changed it to index just give it some time and eventually the hits will return lol

Well, my pages are coming back. Some are at their original positions, some are still first-page but down a couple of spots.

These are the main pages, such as Acme Widgets. What I can't tell yet is what effect the noindex had on the sub-pages, such as Acme model XYZ widget. I'll have to wait until this all shakes out and then run a ranking report.

Thanks for the supportive replies.

Pages with a meta noindex tag are still fetched and cached by Google.

The pages do accumulate PageRank and the links on the pages are followed out.

Once the tag is removed, the pages usually reappear in the index very quickly.