This is not the most original observation, but I am regularly amazed at how fast the Hongdae neighborhood is changing. A few years ago I was avoiding Hongdae because I thought it was beginning to resemble the unholy spawn of Apgujeong and Itaewon -- simultaneously too upscale and too trashy. But lately, I have been more impressed by the neighborhood, enjoying all the new shops it has to offer.
It was not long ago I used to moan about how there were not any Indian restaurants around Hongdae and Shinchon. But today, there are six (that I know of). My favorite is still the original Shanti (close to Hongik Subway Station). And there is Taj (in the Seokyo Building), a spin-off of the original Taj down in Myeongdong. Manokamana is the new place in Shinchon (very similar to Shanti, there is a review of it by Andrew Salmon here). There is the ridiculously expensive place in the white building by the AA Design Museum. And there are two more in the new Calliope Building near the Hongik University main gate, behind the Coffee Bean and the Prugio apartment -- Kaka Kumar (a spin-off of the Ganga chain) and a new Shanti (not open yet, but it looks like it will have a really spiffy patio).
Oh, that Calliope Building also is home to some of the best mandu in Korea
(I refuse to include the India Gate in the Hyundai Department Store in this list, but I have been told that it exists, up on the 10th floor).
(UPDATE: Hrm... could India Gate actually be decent? From their website description, they could be okay).
In addition to the Indian food, there are endless little "coffee & cake" shops, seemingly in every building, between buildings and any nook that can be converted into a mini-cafe. Some of them are actually nice.
And on the Donggyo-dong road, close to the Sannulim Theater, there is an impressive little goth shop called Beetlejuice. Just down the street from there is a very good sake and shochu shop called Syo Syo. Plenty of places for a good drink or a coffee.
There are simply way too many new places to list them all. But one thing that I am rather impressed by is the rising number of patios and open-windowed shops around the area. It used to be a real pain the butt to find a shop like that, but now they are all over the place. The great weather we have been having this spring has helped a lot, too. Very civilized.