CD Projekt has released the patch notes for the coming 1.20 update to The Witcher 3: Wild Hunt, which makes a number of improvements and fixes to the game, including one that will be a big boon for Gwent card collectors: A new book called “A Miraculous Guide to Gwent,” which displays the number of cards missing form your base-game deck, and information on where to get them. New players can get the book from the Gwent scholar in the prologue, while those of you already deep into the action can pick it up from the merchant near St. Gregory's Bridge in the Gildorf district of Novigrad.
Other big changes include the addition of optional enemy “upscaling,” which will make low-level enemies more challenging (but won't affect experience points, loot, or quest rewards), and an increase in the incidence of certain monster-based ingredients required for high-level alchemy. The inventory and journal have been improved to make them easier to use, automatic drawing and sheathing of swords can be disabled, and—this is a big one—there will be a fix for a bug "whereby Geralt's clothing was not properly restored after sex scenes.”
There are quite a lot of other fixes and tweaks, most of them for the base game but some specific to the Hearts of Stone expansion. A rollout date wasn't announced, but CD Projekt Community Lead Marcin Momot said on Twitter that it will be out after this weekend, but “shortly before” the Blood and Wine expansion goes live on May 31, and Tom Senior's review says that it's very good indeed. Full patch notes can be found here, and the relevant discussion of the update on the CD Projekt forums is here.