I think this really one of the best ways to handle this. FNL has got to be one of the most consistently well written and well acted shows I have ever seen. Yes, they did have that rather ridiculous arc during season 2 but heck even that was carried out with more care then most other shows would have done.
Had the series ended with season 3 I would have been content. Yes, many of the characters were starting out new phases of their lives and I would have regretted not being able to see those new phases explored, but I was grateful for the episodes I did get. Many shows don't make it out of their first season and for some reason I tend to get into show that only last 3 seasons. However, with this renewal comes the opportunity to see where my favorite characters are headed as well as what new characters I'll be introduced to. I have no doubt that next two years will be phenomenal.
Now, I've recced the two following FNL vids before. They both premiered at VividCon 2008 but I can't help but rec them again. If you're at all curious about checking out FNL give these two vids a try. I promise you that you won't be disappointed.
Let the Sun Fall Down by chasarumba and New Slang by obsessive24