What happened is at a recent hacker convention a hacker published a brainwallet cracker that is 10-100x faster than any other brainwallet cracker ever published before. Because of this the owner of brainwallet.org finally listened to what people have been preaching for years which is that brainwallets are a dangerous thing for the average person and it's not a good idea to promote their use. You can get the code on github if you need to claim your funds from old brainwallet addresses, but do NOT make another brainwallet unless you enjoy having your Bitcoins stolen, though if you are going to do that I ask that you just give them to me instead.
"Double hashing" is bullshit, people who say "oh you need to do X to make your brainwallet secure" are all full of shit. It is true that most brainwallet generators don't use a strong hashing algorithm, but thats a side issue that doesn't really matter anyways because brainwallets are still insecure as shit even when using a strong hashing algorithm. The only way to make it safe is to use a cryptographically strong random number generator to generate a seed. This will however likely be too long to remember (electrum uses 12 words and thats pretty much as small as you can safely go - 128bits). So basically the problem is the brainwallet will either be easy as shit to crack or too hard to remember, there is no middle ground thus brainwallet = bad idea.