You know who else might be on Doctor Who

OK, Patrick Stewart being on Doctor Who is an awesome call, one of the best stunt castings they'll do. But then, why balance the cosmic karma with this? OK, if done well -- like, a really brief cameo where he walks by and utters one line (think John Cleese and Eleanor Bron in the Tom Baker era's "City of Death") then this could be brilliant. If done poorly, well... we'll know the exact moment my beloved Doctor jumps the Raxacoricofallapatorian shark.