Shelly is a good step forwards and any major release will tend to have a positive impact on price. The quality of the release will be what ensures longevity of the price rise, could just be a case of buy the rumor sell the news.
From the official news revealed about the release of Shelly it has put forth the updates taking place along with it. Shelley phase will include the following developments: multiSig transactions, enhanced Wallet backend, light client mode, networking, paper wallets, consensus and incentive fees, open Ouroboros delegation, quantum resistant, a voting center, and human-friendly addresses. These will surely create a positive impact on the price and marketcap.