The first is at National Cheng Chi University (Taipei), on October 16th, 2010. You can read more about the conference on the NCCU website:
4th Conference on College English - College English Programs: Design and implementation
Scott Sommers, a university instructor and blogger in Taiwan, had this to say about the conference:
I attended this conference last year. It was excellent - easily the best conference I have attended in Taiwan. If you are curious about the conference scene or interested in presenting, this is the number one ELT conference I recommend.
Another conference worth attending is the ETA - ROC 19th International Symposium on Language Teaching (Taipei) on November 12-14, 2010. This year, some familiar names (David Nunan, William Grabe, Stephen Krashen, Neil Anderson, Fredricka Stoller) will be presenting. You can see a complete program for the conference here:
ETA - ROC 19th International Symposium on Language Teaching
On the subject of conferences, Alex Case has some unbeatable advice for making it worthwhile:
Attending TESOL Conferences by Alex Case
Jeremy Harmer has some similar suggestions on his blog:
What Makes a Good Conference? by Jeremy Harmer
Finally, if you're giving a talk, Andrew Wright has some good ideas here:
Some notes on giving talks at conferences by Andrew Wright