I have just finished reading 'Outlander' by Diana Gabaldon and I absolutely loved it!
I posted my review on lilly-readingextravaganza.blogspot.com especially for those who haven't read it yet and here I would like to know what you thought of the series.
Yes, there will be at least two more books in the OUTLANDER series: AN ECHO IN THE BONE, due out in the fall of this year (she's in the final stages of writing this one now), and the as-yet-untitled Book 8. After that, who knows? You're right, Diana has indeed talked about plans for a Master Raymond book. Also a possible prequel volume involving the story of Jamie's parents, but all of that is in the very preliminary stages.
There will also be another Lord John book, titled LORD JOHN AND THE SCOTTISH PRISONER, but we have very little information on that.
I did, I read and re-read and have passed it on to NUMEROUS friends, who always thank me.
A fellow LT reader suggested I try "Into the Wilderness" by Sara Donati, as the first in the Wilderness Saga... I just read the first one and really enjoyed it. Not QUITE up to Gabaldon's standards... but you'll see the similarities in the writing and I think you'll enjoy.