The 30th Anniversary announcements are in full flow, and with Pokémon's birthday happening tomorrow, I believe this is just the beginning of reveals coming throughout the year.
For those who are fond of the original games, such as Pokémon Red, Blue & Green, this news will evoke incredibly nostalgic feelings.
According to GAME WATCH, a popular Japanese blog, Pokémon is revealing a wide range of upcoming items that will be stocked in both phyiscal and online Japanese Pokémon Centers.

Two incredible products that have piqued my interest are the large S.S. Anne Diorama in grayscale (just like the game), perfect for retro game rooms, alongside a grayscale, pixelated fat Pikachu in both large and small sizes.
Pixelated Pikachu doesn't get enough love, and the same goes for the infamous "fat" Pikachu, but it seems like this year it's in the spotlight, seeing as this is the second plushie to be announced that focuses on it.
GAME WATCH mentioned: "Pokémon held a "30th Anniversary Begins" presentation event in Japan today, to commemorate the series. They kicked off with a phyiscal presentation for the media, showing various products that were on display".

Alongside the two grayscale products were Pokémon Red/Green focused merchandise such as pillows, t-shirts, slings and caps (which I want).
It's clear that Pokémon are going all out with merchandise this year, and although most of what you are seeing here is Japanese exclusives and will likely not make its way into the West, officially, we will still be getting some awesome stuff.
Pricing and official release dates for these products are still unknown.