My understanding is that indexed="true" works only for a List or array of JavaBeans. It does not work for a String array. For that, one has to do as you have done and manually construct the indexed property using either scriptlets or EL expressions. [ October 15, 2007: Message edited by: Merrill Higginson ]
That is all I could figure out as well...just wanted to make sure that I was not missing something. I played around with my sample code and the best solution that I could come up for someone that really wanted to use the indexed="true" setting is to create a StringWrapper class that just had a String property named value.
On a side note...I should play around more with Struts EL. It is looking like my project will be stuck with JSP 1.2 support for a while and there are plenty of places where using EL would be handy.