A reform? Would be nice, but forget it. Most governments are quite happy with ignoring conflicts as is... why create a reform that will only complicate things?
Just changing the head isn't going to change a thing. The Rwandan genocide happened under another secretary general. And absolutely nothing happened. They sent the peace corps, but that was pure populism - they can't shoot, basically just stand there as large target with a blue helmet.
The only real successes I can think about when it comes to the UN is the aftermath of WWII and the liberation of Kuweit - both of which were influenced mainly by the US of A and their foreign interests. Besides that, the UN is just a bunch of talking goons that never get anything done, AFAIK (I may be wrong). The conference against racism and discrimination that happened recently is a prime example. Basically, Iran started calling Israel racist, most countries' delegates left the conference and Europe almost opted out. Total chaos. Which nations care about what the UN says anyway?
In essence, the UN is a front-agency of the US of A that can operate under the nomenclature of "internationality". Which is, as we all know, complete horseshit, if you'll excuse my language.
What is needed is an INDEPENDENT organization that can literally blow the lights of any nations out if it so much as peeps - and actually does so if there's any misconduct.
The veto system is outdated, too. India has ~1 billion citizens, but no veto rights??? Hmm... if 1/6th of the world population has no representation in the UN... Oh well, who cares about them as long as the West can keep exploiting cheap labor. China's veto is pretty shady, too (Taiwan vs. PRC). The same goes for countries that barely have a say on the world stage, such as the UK and France. Overall, veto rights are distributed to countries that are able to pay the highest membership fees. Even the veto itself is a pretty strange invention. What is needed: Representation by population. Restriction of the scope of the UN. Nondiscrimination laws inside the UN.
However, human psychology has taught us that even this isn't going to work, no matter how "fair" the system is. Weimar Germany was a democracy but somehow the people still managed to abuse the system - in fact, it was one of the most liberal and modern democracies around (well, except for article 48 - VERY similar to the veto power). You think this is going to work with the UN?
Ok, enough for now. Someone tear down all the arguments I have against the UN and tell me the system isn't so bad...