"We knew in advance that no matter how this decision would come out, a part of the astronomical community would be disagreeing. The intense debate at the 2006 General Assembly was very healthy and exactly intended to make as large a fraction of the community as possible, agree with the decision. In this we succeeded.
It also has to be said that the - now very visible - "splitting" of the community in the issue of where to make the delineation between planets and other solar system objects is not new. It is a debate that has existed for several years."
Going back to calling Pluto a planet will NOT solve anything. Its hard to see what the either the scientific or public naysayers believe they will achieve.
SPACE.com: Has the intense debate strengthened or weakened the authority of the IAU? What does the group need to do to keep its position as a governing body?
It is too early to tell. The IAU has a rigorous set of Statutes, Bylaws and Working Rules. These have been followed carefully in this process of developing the planet definition Resolution and in the voting process.
A controversial subject such as this merits debate as we had during throughout the General Assembly. The astronomers present could ponder on the arguments expressed and prepare for voting. Our Statutes state that Resolutions can only be passed by a majority of those IAU members present and voting. Resolution 5A was passed with a wide majority. There is therefore, from our perspective, little reason to question the authority of the IAU [emphasis mine].
The established rules were followed and the result was that by majority vote Pluto was redefined to be a minor planet. The IAU is a conservative body (conservative with a little "c", in the old [positive] sense that it is slow to change and acts with care, which I note is now diametrically opposite to Conservative in the political sense). This change in Pluto's status was long needed, and not taken lightly.