Good advice, IMO!
Don't base your decisions on what Google is doing, rather make sure YOUR site is running properly. Google will not be OWNING search forever and the best thing(IMO again) to do is play the field now.
If you are dropping in ALL the engines, then take a hard look at your site.
If you are only losing ground in Google, concentrate on making your site better.
I see sites(mine!) take lumps every now and then, only to come back just as strong as ever.
Do check your site out thoroughly for any problems:
- Check that proper headers [webmasterworld.com] are being returned
- Look at your external linking(ie. they MUST be somehow picking up on sites that recip-link heavily and rapidly)
- As mentioned earlier, MAKE SURE you aren't creating dynamic pages that could be misconstrued as duplicate content.(eg. using mod_rewrite to make friendly URLs, but still having scattered dynamic links that will essentially form the exact same document)
Good luck with it,