I know this is an old thread. The problem was new to me, today. I've been struggling with 'tuning up' my computer (rebuilding MS Outlook identities) and something went awry. The indexing never stopped no matter how many reboots.
Never gave a time, just kept the working to figure that out. Nonstop for 10 hours. Everything was slow.
I read countless pages on the net, and Christopher Murphy's post on the bottom of page two seemed likely. I can count on my hand how many times I've used the terminal program. Scary.
I followed his instructions, cut and pasted, hit go, and the first command stopped the madness. Quiet.
I then rebooted, added back in the indexing command again, hit it again, and THIS time it spent a few mins considering the work, and then it had a time status bar which took only 40 mins to completely do the indexing.
It was fixed!
I love the forums for helping, and I want to say thanks and hopefully steer the next frustrated soul to a manageable fix on their own.
I just found the same issue on my MBA. And I solved the problem after some googling.
The cause is from my 64G SD card volume. So I :
Add the SD card volume to Privacy in Spotlight setting. And indexing stop right away.
Then I remove SD card volume from Privacy. Index start and stop under a minute.
That's it. Problem solved.
Hope it might help.
This worked for me. Was still suffering from this problem with 10.9.2 - not causing any obvious slowdown, but irritating nonetheless.
In fact, I didn't remove the SD card volume from Privacy after adding it as I don't really need its contents indexed anyway. Hooray, no more "estimating index time".