I asked this question in the Wisdom of the Crowd:

Should Dr. Tan Cheng Bock set up a new party?

Here are the responses: (74 Votes)
64 % – It is better for Dr. Tan to lead a coalition of the existing non-PAP parties.
16 % – It is better for Dr. Tan to set up a new party and attract its own members.
11 % – A coalition of the smaller non-PAP parties will not be credible anyway.
9 % – The new party will split the non-PAP votes.

See the pie chart at: