For longterm success of Bitcoin project we need to spread this power across more exchanges, make that pie charts above more balanced. Exchanges like Intersango and Cryptoxchange, which are built as serious businesses (not like some anonymous guys from east Europe), looks trustworthy and are promising competitors. Let's see if they'll be successful - it's in the interest of all of us.
Yes, technically. We already have some exchanges built as a serious and professional businesses, such as CampBX or (the now closed) ExchB, but people haven't moved from MtGox. It is hard for new exchanges to get a decent market share, regardless of how professional they look.
Anyway, these companies are 4/5 months old at most so let's wait and see if that pie chart moves.