Nothing weird about a forest fire.;)
I had a funny one once. I once came upon a burning forest, and i was never there. People on forums say, lava sometimes does that.

That's a forest fire. Reminds me of the funny story where I spent an afternoon raising a forest around my stronghold, then figured out how to make steel and flint. I lit off ONE STUMP, I swear.

Yea I've stumbled across a pool of lava and watched as it lit fire to the tree next to it.

The one thing I don't like about those is that they tend to result in me spending ages gathering wood before it goes to waste. Though it's quite a spectacle from a mountaintop when all you can see is fire.

On my current world I've got a forest fire that stretches far beyond the maximum render distance. With the way fire works it will burn forever unless I do something about it. :/

The new ability for spiders to climb walls is worrying. I'll have to make sure my new farm complex is prepared for this. In the past I've had parapets but no overhangs, so spiders could just zoom straight up.

It is a multi server. There wasn't source of fire or lava or what ever.

And yeah, several places cought fire... spawn place, some nearby houses... my Somalia :(

Arson!

Spontaneous Forest Combustion then. ;P It happens. ;D

I've heard people say that they can't climb the new sandstone block. So you could have a line of that intergrated into your parapet.

It's not more downwards pressure, it's to do with the AI. The mobs think they can walk through the glass so they walk into it and sink.

this is just epic...
http://www.youtube.com/watch?v=ewFrgDPCgGA
fun with new dispensers :D

Is there some sort of bug with the squid? I've searched far and wide, but I can't seem to find any in this world.

I need black wool, dammit! :/

They appear randomly, particularly over deep water, as best as I can tell. Doesn't seem to be related to lighting or anything.

According to the wiki, depth or lightning doesn't matter. I just find it odd that I haven't found a single squid, when I've spent days actively searching for them. None of the other mobs are particularly hard to find. :/

Really? Well I remember reading that depth does matter. Though I could be wrong, not even sure where I read it.

But yeah, could be a bug. You could always nudge Notch on twitter or something.