TPCi (The Pokemon Company International) has officially announced the release date for the next phase of the Mega Evolution era for the Pokemon Trading Card Game (TCG).
Phantasmal Flames

In an announcement on their official press site, TPCi has announced that Phantasmal Flames, the second expansion featuring the return of Mega Evolution Pokemon to the TCG, will be hitting store shelves on the 14th of November for their markets in the United States, Canada, Australia, and New Zealand.
According to their announcement, Phantasmal Flames will feature the addition of Mega Charizard X and Mega Gengar to the card pool. This all but officially confirms that this Western release will include the cards from Inferno X and the Mega Gengar Starter Deck.
Potential delay in other markets
Unfortunately, there is an unspoken implication with the release date above. With the mention of specific markets instead of using language like ‘all around the waffectrld’ or ‘worldwide’, there is a possibility that whatever is causing the product delay for the Mega Evolution expansion in the EMEA (Europe, Middle-East, and Australia) markets might also affect Phantasmal Flames' worldwide release.
Keep in mind that this is just an extrapolation based on the language used in their official announcement. We have no official word from TPCi on whether there will be a delay at all or if there is an intentional plan for a staggered release across the different markets.
Phantasmal Flame Prerelease
For players interested in trying out these new cards early, TPCi had mentioned that there would be a pre-release event scheduled on the 1st of November as part of the ‘Play! Pokémon program’ at selected, independent retailers.
Pokemon TCG Live
As for players of Pokemon TCG Live, you’ll be able to get your hands on cards from Phantasmal Flames on the 13th of November. TPCi mentioned that alongside the new cards, players will receive in-game bonuses when logging into the app.
Phantasmal Flames Pack Art

It appears that TPCi may have tipped their hand with the reveal of the card pack art for Phantasmal Flames. Part of the original announcement included the number of new Mega Evolution Pokemon being introduced in this set. From the looks of things, it appears we're getting six Mega Evolution Pokemon in total.
Mega Charizard X and Mega Gengar are presumably taking two of the six slots, as they are two of the advertised cards of this set. Now, it looks like we may be getting a Mega Lopunny and Mega Heracross in this new set as well.
Not only are Mega Heracross and Mega Lopunny featured on the card packs, but their names are specifically mentioned on the filename of the card pack images that TPCi uploaded onto their official press site.