I think Christopher Ecclestone's Doctor should turn out to be a renegade, a time lord who went a bit bonkers, and influenced by stories of the good Doctor, made off with the Tardis, and came to believe he WAS the Doctor, destined to save the universe from peril, until Paul Magann turns up in the Christmas episode and puts him to rights as to who's the REAL Doctor. Ecclestone does seem to be bit manic and barking in the role.
Paul Magann would be dedicated to the series, and i always thought he should have the chance to continue in the role. (Sorry i've probably spelt his name wrong)