Stay in JB and work in Singapore. Earn S$ and spend in MYR ...sounds like a great idea. I'm sure some people are already doing this. Please share what are the issues/problems doing this.
Which are the areas/development/project to consider?

i guess the first concern is your health ! you have to travel here and there EVERYDAY !

I've many colleagues from my ex company who are now relocated to Singapore....

Many have done so for the first few years, and a little after they move into Singapore. The convenience of commuting in Sg is impeccable. However, there are those who decide to 'build their nest' in JB. Am unsure where, but aside from the daily crawl through the entry/exit points, They're very 'Happy' if you know what I mean.. lol.

I'm not familiar with JB, but my friends who live in JB permanently and work in Singapore live very close to the boarder. Guess they can afford that kind of rental la.

At the current exchange rate (x3), it makes more sense to do this.

Anyone familiar with these areas - Aloha Towers, Sri Samudera Jalan Mahmoodiah, Stulang area and Permas Jaya?? Are these areas very near to CIQ to Spore? How is traffic condition in the morning going in to Spore? Permas Jaya is the furthest but cheapest.

This is a very common way of Malaysian who work in Singapore since last time due to living cost in Singapore is higher. But nowadays, living cost in Johor is not cheap either compare to last time.

if u divide it by 3, it will be very cheap...

Updated Jan 2017, it is divide by 3.1 nowadays... recently you will need to factor in RM20 RC (Road Charge) if you travel daily in a SG registered car and S$6.4 RRC (Reciprocal Road Charge) if you travel daily in a Malaysian registered car.

Wonder if more and more people will opt for public transport, travel with motorcycle, or move into Singapore?

Probably public transport will be a better solution..

To avoid the causeway congestion. The Shuttle Tebrau train or the future HSR would be a good alternative to bus or motorcycle...

The cheapest option would be to walk across the causeway on foot.  However,  there was a case where a motorcyclist hit a pedestrian and he died a few days later unfortunately.

@ppnnkk2011 thanks for sharing