Not the world's first litewallet, sorry.
World's first main wallet with the ability to switch to a lightweight version of the client on demand!
With or without a wallet restart?
With a restart would not be a world first either.
Without a restart, I'm not sure and will take your word for it but seems trivial.
Confirming no wallet restart.
Well you have the added convenience of having your cryptos in one place and the same addresses, say if you are travelling to another location where you have bandwidth restrictions, without needing to download and install multiple clients, all at the touch of a button.
Not to mention that our users benefit from being able to keep the same user friendly 'Crypto-Banking' interface that they have grown to love.
But the focus of this update is more about the ability to immediately utilize your crypto without waiting for the blockchain to download and sync with the network. But we've dramatically improved the speeds of this as well.
This is going to be useful for all proof of stake based currencies, say if blockchain files inevitably get bigger in the gigabytes, users opting to use a lightweight client will not be earning interest or helping to secure the network to prevent 51% attacks.