PRG pattern, out-of-the-box support
Built-in support for the PRG (Post, Redirect, Get) pattern. Possibly, through controller action filters ?!, along the the following line: http://weblogs.asp.net/rashid/archive/2009/04/01/asp-net-mvc-best-practices-part-1.aspx#prg
Typically in ASP.NET MVC you redirect on success (thus avoiding duplicate post problems) but not on failure. On failure the action handling the post returns the validation errors. Is redirecting on failure and preserving the errors using TempData a common pattern? Is it perhaps even an anti-pattern?
Bad idea. At my company, we outright ban TempData and all sessions due to the way our load balancing works in high availability scenarios. TempData is a kludge!