Electrum 2.0 was released a while back. Since then there have been a few bug fix releases to this branch as well. Here’s whats new in the Electrum 2.0.x versions:

Support for certain hardware wallets like the Trezor. A lot of hardware wallet vendors have been working to add support in Electrum.

BIP32. BIP32 is a standard for deterministic wallet extended private keys and public keys. Electrum only supports 1 BIP32 account. The mnemonic format has also changed with 13 word mnemonics the new standard.

Multisig wallets. You can now create 2 of 2 or 2 of 3 multisig wallets with Electrum. Multisig wallets are where you need multiple wallets with different seeds to sign a transaction that spends bitcoins. So for example you can use two PCs you own and both will have to be used to sign any transactions. This is an example of 2 factor authentication using multisig. Another example is a shared wallet where 2 out of 3 individuals must sign off on the transaction. Electrum also has a feature where partially signed multisig transactions can be stored in encrypted form on an Electrum server. When the other wallet holders go online they are shown the transaction and offered the option to sign it. This feature is provided by the co-signing plugin.

2 factor authentication with Trusted Coin. This is a multisig implementation where a 3rd party company called Trusted Coin holds one of the seeds of a 2 of 3 wallet. They promise to sign transactions as long as you provide the correct 2 factor authentication code using Google Authenticator, Authy or other TOTP application. I’ve tried Trusted Coin in the past with their SMS based 2FA service and they failed to send me my authentication code! Their support was also not helpful. Maybe their Google Authenticator based service is better because it does not rely on mobile phone networks to deliver SMS. Instead the code is generated independently using a shared secret.

Sweep private keys option. Paper wallets are, unfortunately, very popular so Electrum has added support for properly spending from them. This option sends all the bitcoins in your paper wallet to an address in your electrum wallet. It does this with an on-chain transaction.

Encryption and decryption of text. This was first implemented in the 1.9.8 branch but gmaxwell found that the crypto was unsafe so Electrum dev ThomasV switched this feature off. I guess it must be safely implemented now.

Conclusion

2.0 was a pretty major release and since then there have been 3 point releases. I cannot really recommend the 2.0.x versions just yet. They still have a few bugs in them but they’re fun to play around with! In time they’ll mature and we’ll be able to enjoy these awesome new features.