MVC or MVP for an existing site, upgrading to .Net

I'm in the process of upgrading my website from classic ASP to .Net 4.5 (VB), and having trouble deciding on a pattern.  I was planning to use MVC, however, MVP is also an option.  My website:

- uses all SEO friendly URLs that I HAVE to retain, set up in the web.config eg.  www.mysite.com/lawn/2013/04/seeding-and-watering
- do not want to 301 redirect to URLs for a new pattern, so will either need to use custom routing or IIS URL Rewrite
- high traffic, with over 1m pageviews per month.
- existing database and data structure
- site performance and page load speed are paramount
- 100s of pages on the site.  Most of them are dynamic, pulling content from the database 
- users interact with the site through the forum, commenting on articles, and registration/payment forms
- heavy client side scripting with jQuery and other SDKs

Couple other points:

- would like to easily make a mobile version of the site
- produce web services and API
- our products change frequently, requiring code and database modification regularly
- transitioning to HTML5

Any feedback on which pattern would be ideal for my situation is appreciated, including reasoning behind choosing one or the other.   Looking for pros/cons of either option, and which pattern is better suited for specific types of projects.  I've read several articles on this topic, and posts in forums, but still am undecided.  Thanks for your help.