As of this writing, both Poloniex and Steem wallets are disabled. Binance shows the Steem wallets down for maintenance and Poloniex shows it as temporarily disabled.
How long the wallets will be disabled is anyone's guess, but I just didn't want anyone to send any money to these exchanges expecting to buy Steem and find out that they couldn't get their Steem out of these exchanges at this time. Hopefully, this post will save somebody a transfer fee/exchange fee when transferring to these exchanges and then making a trade to buy Steem...only to find out that they cannot get their Steem out.
If anyone sees these big exchange's Steem wallets come back up, let us know. This post may be one of those resteem types of posts...so please feel free to resteem it so that it gets broad visibility.