I have been thinking a lot this morning about all of our trips and how our plans always change once we get to the world for various reasons. I devour all things Disney but the websites, podcasts, and books can only give you so much. The people that offer this information do not know you or your family and can only predict things. Sometimes even Disney doesn't know what will be happening on any given day. With respect to WDW and vacation plans, personal experience is invaluable.
The following is a list of items that have adjusted our plan each year we have visited:
1) in 2009 I didn't expect record level rain because accuweather nor weather.com expected it. The rain prompted a lot of indoor character meets, rudeness in guests, and the ability/desire to visit indoor attractions we would normally dismiss. I also didn't expect to meet so many great DIS friends....definitely a highlight.
2) In 2008 I didn't expect an impromptu character meet would cause me to miss an ADR because it was so magical (all ears, the DIS, nor Steve Soares told me I would be meeting these characters in this location)
3)In 2007 I never expected our bus to breakdown or the weather to be so beautiful that we were able to stay at the parks and not need rests. I also was advised that the castle package at BBB wasn't worth it. Despite the advice, I booked it anyway. Let me tell you, the look on Lindsey's face and her excitement when her FGM opened the door to the dressing room with her dress, wand, shoes, and tiara laid out before her was PRICELESS. Josie had the same reaction in 2009. I will continue to pay the $100 extra despite the opinions of those who hadn't, in most cases, even experienced the full package.

You can't put a price on the memories we've made with a complete princess makeover in the most magical place on earth. That's just MY opinion and still brings tears to my eyes as I type this.
4) In 2006 I didn't expect record level crowds and heat because touring plans nor weather.com expected it. Because of the heat the characters were all over the place and not where the Times Guide, the DIS, nor All Ears told me I could find them. For example, we met Snow White & Dopey, Belle & the Beast, and Aurora in the courtyard to the UK when the Times Guides said Germany and France.

It was great though because most people couldn't find them, there was NO line, and they spontaneously got together for a group photo with my girls. If it weren't on my external hard drive I'd post it...it's really special.
5)In 2003 I didn't expect the crowds to be so low that we did everything and actually got the chance to check out Sea World
6)In 1999 we didn't expect our extended family trip to be affected so much by waiting on others and illness
7)In 1987 I didn't expect to only ride 4 or 5 attractions per day due to crowds. We didn't even travel during peak season.
I could go on and on because I too scour websites, the boards, religiously listen to podcasts etc. I use this information to put together a game plan but I have learned (the hard way) that ALL plans will be revised when you get to the park. THAT is the real magic of Disney. Something unexpected can happen almost any time, almost any where. No two people will have the same exact experience. That's why we keep going back.