Yes, it is. v1.1.0 "Thunderstruck" is the preamble to Lightning Network and involves a new vote agenda. Earlier versions risk being forked off the network if the vote passes once the new opcode is used. The hope is to start voting by October 1st.


No reseeding of your wallet is required, and you certainly don't need to download the blockchain again if you already have it. Just download, install, and you're good to go!