Correlation between deep-indexing and SERPS rises?

[dangerman]

Be interesting to know from those of you who have suffered a major drop in both pages being listed and SERPS whether a big comeback in site:domain.com numbers was a precursor to a return to pre-drop SERPS?

My biggest site had around 16,000 pages included. This dropped to around 600 a couple months ago and accompanied by hit in SERPS. But a few days ago all pages seem to be indexed again, but yet no difference in SERPS on sitename or any keyword combinations therefore no traffic increase. One would think this was a good sign but who knows..?