Hougang with a comfortable margin of 12.7 % in 2006 to remain in WP hands. Aljunied scraped thru in 2006 with 6.1% is expected to fall to WP which now has a star studded cast. This means that house will now have 6 opposition against 81 PAP MPs.
Looks like Tampines is apparently not an issue for two reason - 18.5% margin from 2006 and guess what - highest number of new citizens in the constituency. If GMS and team reduce the margin by 10%, they would have done a tremendous job. GMS is also stifled by the fact that he does not have quality by his side.
Opposition major issue is the unexpected good quality of candidates and the inability to allow focus.
Here is why Marine Parade is a major issue for the PAP. It had not been tested except for a 1992 (nearly 20 years ago) by elections when their main competition fail to complete forms on nomination day. In 1991 when it was last contested in a GE, PAP did very well with a margin of 27.2% but against a group of total unknowns. Their intelligence had indicated that it would not be contested. They therefore decided to give a few MPs and ended with Ms Tin thinking it was safe bet.
My take is different from yours. You should not omit other GRC where there are equally capable opposition candidates. I expect Holland Bukit Timah GRC with very strong opposition team to kick out Balakrishnan. The YOG budget is Vivian own graveyard. If he think he can get credit out of YOG, he is over-estimating his credibility. Besides, he has been consistent in dressing down Singaporeans thru his parliament and other speeches - that alone spells doom for him now that the power lies squarely in the hand of those he detested.
Bishan Toa Payoh, a flow over from Potong Pasir might just bring Chiam back to parliament again. If Hougang can spill their support base to Aljunied. Same apply to potong pasir spill over to its neighbouring town.
Marine Parade and Tampines are closely watched - Tin Pei Lin and Mah Bow Tan is PAP toxics for now.
Other GRC and SMC where WP are contesting. NOw that WP has garnered popularity in Singapore, it might spill over to their support base in other constituencies like Kallang Moulmein GRC. I heard arrogant Liu Tuck Yew is not a popular candidate among the residents there.
The ideal result is that PAP may just lost half of its power in parliament. An ideal situation for Singapore and its people.