Hoi,
I had an interesting conversation with Brion. We do not agree on everything. One of the things we do not agree on are redirects.
In my opinion, Wiktionary should not have redirects. A word is either spelled correctly and it will have its lemma or it is not and there will not be a lemma with the incorrect spelling. In Brions opinion there are links to lemmas and as we need to ensure that these links remain ok, we need redirects to make this possible.
In a Wikipedia context I am 100% with Brion. In a Wiktionary context it is a different matter. As only correctly spelled words should be in a Wiktionary, errors should be deleted. Some of our Wiktionaries for historical reasons are capitalising their articles. In essence this means that from a spelling point of view the name of the lemmas are irrelevant. However, many people assume that the name of the article indicates that a word is spelled correctly. To remedy this, more and more wiktionaries are moving away from first character capitalisation and make it possible to have correctly spelled words as a lemma.
When a wiktionary has made this move away from first character capitalisation, the interwiki and interproject links within the Wikimedia projects need to be fixed. After this, the redirects can in my opinion be removed. I think this is appropriate because users expect that an application behaves in certain ways. When new content is added to a non-capitalised Wiktionary, the word foo will not have a redirect in Foo and consequently it behaves differently from the content predating the move to non-capitalisation. Also words like Kinder and kinder are not related at all. The redirect at Kinder will be replaced at some stage breaking the existing redirect and consequently not providing the continuance that Brion holds dear.
For the Ultimate Wiktionary I have documented some of the design criteria. It can be found here: http://meta.wikimedia.org/wiki/Ultimate_Wiktionary_decisions_on_its_usage The Data design can be found here: http://meta.wikimedia.org/wiki/Ultimate_Wiktionary_data_design
One crucial decision is that only correct spelling is allowed. This means that all incorrect spelling will be amended or deleted. As Ultimate Wiktionary is a database, it does not cater for things like redirects. I urge you to have a look at both the design criteria and the design itself because this is the time when it is relatively easy to make changes. Once Erik starts coding the UW database, having finished Wikidata and the GEMET implementation, the moment has passed us by.
Thanks, GerardM