I wouldn't say I'm blown away, but I certainly appreciate seeing art in public to both enhance the atmosphere and for creative inspiration. Using the posts / stories search engine I came across this article:

http://www.indy.com/posts/3888

It covers some information about Opie's cultural trail animated sculpture, but doesn't exactly answer your questions.

When using the photos search (it's at the bottom of the dropdown to the left of the search box) I came across some pictures of his work including one submitted by "Public Art Indianapolis". I didn't realize they had created a profile on the site. You'll find information about how the Julian Opie public art came to be in their bio:

www.indy.com/people/PublicArtIndianapolis

Yeah, I first saw one of her pieces all jazzed up in the middle of the Valta River in Prague. The next month I moved to Indy saw the street walkers hanging out on dry land. Funny!

I'm with you, ronlewhorn. Julian Opie's public art has added immensely to the urban vibe here, in contrast to its predecessor, Tom Otterness' cutesy, lumpy, cartoonish figures. What caryatids were to the temples of ancient Greece, Opie's walking and/or undulating figures are to our urban architecture and its enlivenment by the people who walk into, out of and just past it on their way to thousands of unknown destinies and destinations. Opie puts the shimmer in our shapes, a glowing line of poetry into our more prosaic avatars of animation!

I'm more in agreement with this post re. Opie. http://www.indy.com/posts/4706 They are much better than that dopey Otterness garbage, but still pretty uninteresting to me. They don't excite me much at all.