I just went to install the latest version of bitcoind and discovered that Wladimir has signed the https://bitcoin.org/bin/bitcoin-core-0.12.1/SHA256SUMS.asc file with a new GPG key: https://bitcoin.org/laanwj-releases.asc. His previous key was https://bitcoin.org/laanwj.asc.
Some Googling turned up this notice on reddit but he doesn't say why he started using a new key. Does anybody know why he switched keys? Are there any good reasons to switch keys? Should I be worried?