In 2000, politicians complained that ICANN didn't add .xxx, because it would allow pornography to be filtered. In 2005, politicians complained that ICANN wanted to add .xxx, because it would allow kids to find pornography. Who knows what will happen in 2010.
A somewhat snarky view of the history so far:
1. ICANN tried to set up a rational policy for adding new TLDs. (Never mind that this was doomed from the start, as there is no rational policy which would result in that outcome.)
2. They received many applications (including .xxx) but none of them scored very well.
3. So ICANN lowered the bar and decided to go forward with a bunch of applications: .cat, .jobs, .mobi, .tel, and .travel. (Judge for yourself how successful these have been.) .xxx initially made the list and ICANN entered contract negotiations with the proposed registry operator.
4. Under political pressure, ICANN's board of directors decided at the last minute not to finalize the contract with ICM Registry for .xxx.
5. The registry asked for a review of ICANN's decision from an independent review panel, as laid out by ICANN's bylaws.
6. The independent review panel concluded that ICANN had violated their own policies by making an arbitrary decision to cancel .xxx. Unsurprisingly, the arbitrator chosen by ICANN disagreed.
7. ICANN, in true ICANN spirit, opened up another period of public comment about whether they should follow the independent review panel's findings (and permit .xxx), accept the minority opinion which said ICANN didn't do anything wrong, or some mushy third option as a compromise.
8. Now, on Friday, ICANN's board of directors will vote to do whatever they damn well please, as usual. But it might be to approve .xxx, six years after the start of GTLD submissions.
If you're confused about the decision-making process, you are not alone.
Not to mention that .xxx is more or less a horrible idea. Lauren Weinstein calls .xxx a ghettoization proposal and says that "Dot Ex-Ex-Ex is for Chumps". I made similar arguments in my 2002 policy paper about all the special-purpose TLDs, although the term I used was "content segregation". (And I wish I'd found the PFIR statement back then!)