I'd really given it a deep thought before I decided on any activity.
Yip's - Toddler Music Course (2 years long) - will complete in March 2012 as scheduled - plan to enroll him with Hong Kong Children's Choir in Jan 2013 and keep him in the church choir throughout the years.
JMC (2 years long) - will complete in August 2012 as scheduled. Plan to promote to JAC/JXC.
Hooked On Phonics - currently finishing Grade 2 - will complete Reading Club by summer 2012 and then register him with Science Workshop.
Drawing at Lo Fung Art Gallery since 3 - will certainly continue (although my son shows much more interest and talent in languages, math and music).
Enopi Math since three and a half - will certainly continue till lower grades (when there may be more advanced/suitable math programs for him); plan to enroll him with a chess school at 5-6.