Know-How Exchange : Research/Metrics

Conversion rate.
Traffic.
Bounce rate.

* Inbound links
I.e. high quality links by respectable bloggers or news sites, if your website offers useful content for your prospects. It should be a metric of how interesting people think your content is.

High quality inbound links are also crucial to improve your pagerank/SEO, and will in turn lead to more traffic (and hopefully conversion etc.)

*Newsletter subscribers
If people think your site is interesting and you offer something worthwile, they should be willing to leave an e-mail address. As Levinson says in "Guerilla Marketing": "the point of marketing is to get permission to send more marketing".

Agreed with Jay. For a Dutch B-t-B company, we added the following:
a) number of online information/catalog requests, and website visitor conversion in this regard
b) number of online quotes requested, and website visitor conversion in this regard
c) online-to-offline conversion: because many B-t-B buyers enjoy early search online, but prefer to negotiate prices and details with a life salesperson, our company saw most of its online efforts translated in 'offline sale'. The website redesign evaluation should take into account what happened with this conversion as well

Good luck!

When you are looking to measure the success of a redesign, the first thing to look at are your goals. What do you want people to do when they get to the site? Are you trying to get people to sign up for your newsletter, watch a video or do something else? The metrics you look at should be tied to your goals.

Can you tell us about the goals and objectives for the redesign?