The idea of amending or revising the 1987 Philippine Constitution has been around for quite some time. In a number of times that it has been discussed broadly, the discussions focused on the personalities who were espousing the proposal as well as their supposed motives.
In at least two cases where Constitutional Revisions or Amendments were discussed widely, the one's identified as being the backers of the proposal were elected Presidents and fears were floated that it could lead to a succession of term extensions -- something that is not allowed in the present Constitution.
The single six year term provision is widely regarded as a reaction to and a means to prevent another 20 year dictatorship. The thing is the framers of the Constitution probably think beyond the exigencies of the moment and perhaps responded more to what they perceived to be "the call of the times".
What most people don't realize and probably won't believe is that the circumstances that led to the Marcos dictatorship were very peculiar and perhaps would be nearly impossible to achieve again. Marcos' rise to power is as much as a fluke as the so-called revolution that ousted him.
Anyway, given that the county's President has a single six year term, the country is basically locked in for six years and with hardly any way to compel or condition the performance of the President.
Right now, there is an ongoing brouhaha over President Aquino's approval ratings slide and while there is a tililing rampage over it, it won't really affect anything since Aquino doesn't have to worry about being re-elected anyway. His approval ratings can go in the negative, for all we care (like his predecessor's), but it doesn't matter because he doesn't need an approval rating to maintain power.
Impeaching a badly performing or non-performing President, as the past few years of Gloria Arroyo's term proved several times, is nearly next to impossible.
Perhaps, in reaction to this limitation of the present Constitution and its provision on the President's term, there is some reason to revive discussions on Constitutional reform to either shift to a Parliamentary form of government or amend it so as to allow re-election for the President.
A shift to a Parliamentary form of government would allow for a change of leadership based on necessity rather than a fixed term. Parliaments can change Prime Ministers just by a mere vote of its members. (Of course, you'd have to assume that those deciding on whether such a change in leadership is necessary are principled people.)
Amending the constitution to shorten the term of the President to, say, 4 years and then allowing re-election for a second term of another four years would probably compel Presidents to respond to approval ratings since these ratings would indicate their ability to seek another term.