As of r37270 [1], the prop=links, prop=templatelinks, prop=langlinks, prop=extlinks, prop=categories and prop=images modules have limit and continue parameters, just like the list= modules do. This means they no longer list all links/templates/whatever on a page (which can be bad for the database), so you'll have to use the old query-continue song to get them all. Note that this doesn't hurt backwards compatibility, as pre-r37270 versions of MediaWiki will just give you all results at once, without a <query-continue>. If you really must know in advance whether these prop= modules are limited, use action=paraminfo:
api.php?action=paraminfo&querymodules=links
If the limits aren't in effect, the limit and continue parameters won't be listed (if you get an error about paraminfo being an invalid action, the limits are also not in effect, of course, since the introduction of these limits predates the introduction of action=paraminfo by a long time).
Roan Kattouw (Catrope)
[1] http://svn.wikimedia.org/viewvc/mediawiki/?view=rev&revision=37270