Can old sites recover "Trust Rank"?

Hope for sites filtered out of results for a long time

[Whitey]

Following on from another thread at [webmasterworld.com...]

Assuming that the task to recover is harder over time as filters repeatedly kick in and get scored into the data history of a site, I wondered, can such sites recover "trust rank" with good changes?

What are the practical experiences of webmasters recovering from historic patterns that have affected their websites?