I've attached a prerelease build of v 5.2.9 with databinding support.
To do databinding for a control in the FileTemplate, handle the ItemTemplateCreated event. You can use FindControl within this event to find your control, wire up the data source, and call databind. For a FileTemplate like this:
<FileTemplate>
<kw:FileListRemoveLink runat="server">[x]</kw:FileListRemoveLink>
<kw:FileListFileName runat="server" />
<kw:FileListValidationMessage runat="server" ForeColor="Red" />
<asp:DropDownList ID="dropDownList" runat="server" />
</FileTemplate>
You might bind it up like this:
protected void SlickUpload1_ItemTemplateCreated(object sender, TemplateEventArgs e)
{
DropDownList ddl = (DropDownList)e.Item.FindControl("dropDownList");
ddl.DataSource = new string[] { "test", "items", "last" };
ddl.DataBind();
}
One caveat with this is that the template is only created once server side, and then applied for all of the files selected. If you wanted to have a different set of items for each list, you'd need to use client side databinding with AJAX.
Let me know if this works for you.