California is still the hotbed for yoga "stars". if you want to do a week long intensive, here are some great teachers to check out:
www.poweryoga.com
www.seanecorn.com
www.movingintostillness.com
www.sacredmovement.com
www.maxstrom.com
www.yogaworks.com
www.mahayoga.com

Toronto has some funky yoga going on as well. Try:
www.downwarddog.com
www.theyogasanctuary.net
www.yogastudio.net
www.yogacentretoronto.ca
www.iyengaryoga.ca