17. A computer storage device comprising executable instructions that, when executed by a processor, provide per-user aggregation of content, and perform a method comprising: receiving a request for metadata relating to at least one content group accessible via a personalized user site; determining whether the requested metadata is expired by comparing metadata residing in an aggregated list to a pre-determined staleness interval; returning at least a portion of queried metadata prior to verifying whether the metadata is expired; querying a change log for metadata modifications; if metadata has been modified since a previous query, sending a query to a community site for metadata that meets change criteria; receiving the changed metadata; and returning the changed metadata to a content group container within the personalized user site.
17. A computer storage device comprising executable instructions that, when executed by a processor, provide per-user aggregation of content, and perform a method comprising: receiving a request for metadata relating to at least one content group accessible via a personalized user site; determining whether the requested metadata is expired by comparing metadata residing in an aggregated list to a pre-determined staleness interval; returning at least a portion of queried metadata prior to verifying whether the metadata is expired; querying a change log for metadata modifications; if metadata has been modified since a previous query, sending a query to a community site for metadata that meets change criteria; receiving the changed metadata; and returning the changed metadata to a content group container within the personalized user site. 20. The computer storage device of claim 17 , the method further comprising: inserting the changed metadata into a data view of the personalized user site without reloading the entire site.