The Silly Season so far:
Mercedes: World Champion -- Gust of Wind
Ferrari: Sebastian Vettel -- #2 driver
Williams: Felipe 'Fred' Massa -- Valteri Bottas
Red Bull: Daniel Ricciardo -- Daniil Kvyat
Force India: Nico Hulkenberg -- Sergio 'Where is Martin Whitmarsh' Perez
Renault (formerly Lotus): Kevin 44. Magnussen -- Jolyon Palmer
Toro Rosso: Carlos Sainz -- Max Verstappen
Sauber: Giedo Van Der Garde -- Giedo Van Der Garde
McLaren: Samurai Jack -- Jenson Button
Manor: Bernie Ecclestone -- Jean Todt
Haas: Romain Grosjean -- Esteban Gutiérrez
As far as the Silly Season goes, there isn't too much to be excited about given that everyone is still under contract for a while. I wouldn't expect any moves until next Winter, provided the grid closes up as we all hope it does.
Haas is a new entry into the sport; headed by Gene Haas of NASCAR fame and a close technical partnership with Ferrari, the team should be poised to enter the mid-field pretty quickly. The signing of Romain Grosjean is a huge boon for the outfit.
Lotus has been reacquired by Renault following the falling out between Renault and Red Bull. Unfortunately they're keeping Maldonado for another season, but they've decided to sign the 2014 GP2 Champion, Jolyon Palmer.
As for now, enjoy the wait until we get into Winter Testing and find out the Mercedes Power Unit is even stronger than before!