No, it's not but would people be willing to PAY for a better system?
If the SQL database that is used to pomulgate NOTAM data (I'm presuming it is a SQL database) was made publicly readable then they could "open source" the software.
I'd be more than happy to provide a web interface to it, so that you could click nav points and it would query the database providing appropriate data. Maybe it's already publicly readable ? If so, I'd love to know the details...
You could simply provide the web interface as a "not for operational purposes" and give the disclaimer that the archaic ais web site is used. As the open souce alternative progresses you will almost certainly see it overtake the official outlet. Making NOTAMs easier for everyone.
Although the current AIS system is alright once you know how to navigate it I don't think anybody would deny making it intuitive would help everyone. You could point almost anybody at http://news.bbc.co.uk and they would be able to find the current lead story in asia, without any training. I don't think that almost anybody could be pointed @ ais.org.uk and told to find any NOTAMs for Farnborough and succceed ?