1. Do you think it even needs updating at all?
Yes, as you said it's starting to look a little dated in the age of widescreen monitors. I don't think it was ever designed to deal with 27" iMac monitors and the like. Not so much a problem for me as Safari defaults to a square layout anyway. The sheer vast quantity of information could be a little intimidating for a newcomer as well.
2. What elements of the front page do you really LIKE, and would hate to see go away and/or change.
I like the feel of the constant incoming updates, it makes it feel like the page is updated regularly. The random stuff box irritates me slightly. Also, match the links at the top in the same order as the links at the top of the forum. I sometimes just dart for the top and end up clicking the wrong link in either the forum or front page.
3. What elements do you feel are MISSING from the front page?
Twitter/Facebook feed. A slider like in the Graphene Wordpress theme. An example can be found here. I feel it allows the page to 'pop' a little more, it makes it feel a little more alive. In fact, it might be worthwhile, just converting the front page to a Wordpress Blog, and then plugging the back end into PHPBB for the forum.
4. What other changes would you suggest?
Colour coding for different types of news. i.e one colour for industry news, a colour for parks, a colour for rides, a colour for rumours, a colour for trip reports. It would allow people to identify the content they want to see more quickly.
EDIT: After going through the entire thread it appears that there is a bit of an age divide going on. GENERALLY, and I mean generally, people over the age of 25 are saying stick with it, whilst those under 25 are saying change it. Just maybe something to factor in that young people probably want it to look more like the modern websites they encounter on the internet daily, ones that look happy on a laptop, iPhone or iPad.
EDIT 2: Going back to the Graphene idea, with the website I linked to, you could quite easily modify the theme colours, slap the TPR logo on the top and it would look similar, whilst different to the current page, whilst achieving the purpose you wanted.