Agreed. And in fact, if rumors are true, and page load speed becomes a major factor in SEO, then most CMS software will start ranking lower than static sites. Mostly because all of hte DB queries CMSs do really slow down the page load.
Some Help .. but some dont .. .. depends .. CMS are easy to customise and acc to me are better than static sites... My friends above say .. cms slow down the webpage loading which is true .. but we can always go for a light weight framework .. .. ex.. Vbulletin Forum CMS .. most big forums also use .. an extra plugin - VbSEO (its not free) .. coz VB is not that SEO friendly .. .. With Wordpress we use .. All in One SEO .. or .. Platinum SEO .. they only help in SERP Rankings
No. i dont thinks so any CMS help you to gain SERP. CMS is helping us for better account management. now a days if your site is loading speeder then it will help you in gaining better SERP.