The upcoming 1.0.4 release of popular has a few more options
[ ] Show tab?
Location ( ) left / ( ) middle / (x) right
[x] Show Forum-Tab Sub Link?
[ ] Show Footer Link?
XenForo navigation tab only has 1 hook location
Code:
<xen:hook name="navigation_tabs_forums">
<xen:if is="{$visitor.user_id}"><li><a href="{xen:link 'forums/-/mark-read', '', 'date={$serverTime}'}" class="OverlayTrigger">{xen:phrase mark_all_forums_read}</a></li></xen:if>
<xen:if is="{$canSearch}"><li><a href="{xen:link search, '', 'type=post'}">{xen:phrase search_forums}</a></li></xen:if>
<xen:if is="{$visitor.user_id}"><li><a href="{xen:link 'watched/threads'}">{xen:phrase watched_threads}</a></li></xen:if>
<li><a href="{xen:link 'find-new/threads'}">{xen:phrase whats_new}</a></li>
</xen:hook>
So I can't really put it in front of What's New. It will be listed at the end. And personally I don't want it as the first link, in front of 'mark forums read'.
If you have a solution perhaps, please do let me know.
I thought about this myself a few time, but can't figure out how to have a switch for what's new / popular.
If you want to get the 1.0.4 b7 build as xenfans runs it now to test/contribute to, please let me know I can give you a dropbox .zip | I can hold of releasing it after the weekend in wait for you returning the contributions.