NO. Many resellers host dozens of domains with the same IP and non of the domains are affected by this.
Each domain gets its
PR based on individual domain values and you have nothing to worry about using the same IP with multiple domains.
As far as traffic goes chances are you wont get any extra traffic to any new domains unless you submit them to the search engines. However, I have noticed that by using the same IP with multiple domains any domains I add to the shared IP gets robots.txt hits by Google, Yahoo, Ask Jeeves, and a few more.
Hope this helps!
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