Ah, the long awaited sequel to Toaru Majutsu no Index finally came, and it was well received. For fans of the first season- you are in for a great ride... ending with the promise of a sequel (well, if they don't have one, I may have to commit seppuku, because they set it up for one soooooo well). Some of the main complaints about the first season- "Oh, they just go from one girl to the next, never really progressing the story line," "they just ignore so many awesome characters," etc. - are fairly well adressed. Anyways, on to the actual review....
Story : 9/10
Near the beginning of the season, I began to fear for this season because of an increased amount of ecchiness, which was not needed by any means. However, as the season progressed, they kept on track with the story and this problem began to resolve. As things develop, you begin to see where this season is going, and that there will be another season. This, however, is ok, because the way they set it up, what is going to happening the next season follows quite well... it even follows quite well from the end of the first season. As the lines are drawn, you can see where individual characters are going, and it seems... right that they go where they do.
Being a JCStaff series that basically drained all resources that they had, you would expect good animation. Well, that is what you get. Great character designs, cool attacks, and smooth motion in an action heavy series. You get the picture.
The series already started out with a large set of strong voice actors, but they managed to add a few more big names, Kugimiya Rie in particular, to the cast. Along with some catchy OPs and EDs, a good sound track and a lot of fitting music, the sound could only get slightly better.
This series has a large number of really great characters. A lot of the characters are well developed and fairly likable as well. Unfortunately, certain awesome characters (biribiri and Accelarator) don't really get the screen time they deserve. The last arc or two begins to correct this at the very least. Also, a lot of the characters that got their own arcs in the first season, for better or worse, are more or less ignored with little to no screen-time.
Anyways: Overall: 8.5/10
If you enjoyed the first series- rejoice! There will be even more to come. If you thought the first season was good but fell short somewhere along the line (probably somewhere in the teens, episode wise), I would say give this series a try as well. Either way, I look forward, happily, to S3.