If you want to enable the new Rating feature in SP2010 through your custom webtemplate, you have to do two things:

Add site collection feature to your onet.xml (<SiteFeatures>):

<Feature ID=”915c240e-a6cc-49b8-8b2c-0bff8b553ed3″ />

Add these two site columns to your content type:

<FieldRef ID=”{5a14d1ab-1513-48c7-97b3-657a5ba6c742}” Name=”AverageRating” />
<FieldRef ID=”{b1996002-9167-45e5-a4df-b2c41c6723c7}” Name=”RatingCount” />

On lists where this content type is bound, the Classification setting will also automatically go to Yes 🙂 It only checks whether these two columns are available.