We're thinking of launching several blogs in our niche and 'building them up' organically, and then linking naturally from them to our sites (very conservatively). I was wondering if we should buy entirely separate hosting for these blogs and how important are separate ip addresses and class c subnets (shown on majestic SEO tools for instance). Is it possible to create a set of authoritative blogs in a niche and have them be a little 'neighborhood' within the same shared hosting provider (obv similiar class c or even same ip).

actualy I lost about 10 places on my main keyword; strangely NO other keywords were affected and long tail traffic did not get adjusted as well.

no, and I noticed that merchantcircle, one of their 'top 25 biggest losers' still ranks quite well for long tail service-industry queries.

digixmas has a decent article submitter and directory submitter, but this obviously produces mediocre-low level quality links. It does have tools for checking the submission and outputting the exact url of the link, so that you can use services like linklicious or other indexing/spidering services to expedite google's finding these links. The results range from 0-38 PA in OSE. Obviously using these tools won't get you ranked in highly competitive niches, however you could probably achieve top 10 in somewhat competitive local results such as 'industry + cityname". If you're going to use these tools, i would strongly recommend using the submission report features I mentioned otherwise your links will not be spidered for a LONG time.