Last night, Matt Cutts from Google tweeted they have "released the biggest refresh of our spam report form in, oh, say 10 years." Indeed.
Here is a picture of the new page:

As you can see, they break it down by type of "spam":
- Paid links - This page is selling or buying links.
- Copyright and other legal issues - This page should be removed under applicable law.
- Objectionable content - This page is inappropriate.
- Personal/private - This page discloses private information.
- Malware - This page is infected.
- Phishing - This page is trying to get sensitive information.
- Other Google products - This page abuses Google products other than Search, e.g., AdSense, Google Maps, etc.
- Something else is wrong This page has other, non-webspam related issues.
Plus they have a button at the bottom that reads, "This page is really webspam. Report Spam."
Then each form has specific fields they want you to fill out related to the topic. Should make it easier for Google to route the reports to the appropriate groups, thus making it faster for Google to take action.
The old form, which Matt McGee posted a picture of is here:

Google has many ways to report spam and keeps adding new ways. They tend to work for some and while many SEOs won't use it.
Forum discussion at WebmasterWorld.

Comments:
Black Seo Guy
08/04/2011 02:00 pm
I like it because the crap that keeps getting index is mind boggling because it hurting the net and not adding value. "Black Seo Guy "Signing Off"
Jose
08/04/2011 02:24 pm
so where will i categorize spam blog comments? Objectionable content? how will that affect the spammed site?
SpareFoot
08/05/2011 04:37 pm
If they were accepted, they're not spam. If they were injected, I'm guessing "malware"?
web tasarım izmir
08/17/2011 08:16 am
can anybody tell me what is spam site, who deceides a site is spam,
tonyquaid
08/20/2011 01:04 am
I think this is way over due but still not done right and Google should have listed on the Paid Links page the top 20 types of spams people do report and what the definition is of each one with a possible YouTube video explaining each type of spam and showing an example of each one. This would help clean up the internet as webmasters and people would know what to look for instead of just guessing that something may or may not be spam.