They're still only up to book 4 with the English versions, with a new one coming out about every 6 months or so, so it will probably still be a while unless you can read Japanese.
Just...a month away... I dearly hope this isn't the final novel, because Tanigawa leaving us on hold for almost 4 years and calling it the final book is just wrong.
Tanigawa could be totally sick of the series and rush it to a premature end, but story wise it shouldn't be the last one. There would simply be too much development left out, plot threads, and open ends remaining if he did that. Then again, he had no problem leaving behind any of his other series, although that may be due to editorial decisions or Haruhi becoming so popular.