From any page in any language version, the "View Normal Wikitravel" button at the bottom takes you to the Main Page of the English version, making it difficult or impossible to view other language versions on the non-mobile site from a mobile device.
Actually, it doesn't necessarily take you to the English version. It takes you to whatever version matches your browser language. This is not how Wikitravel (or any wiki) should work - users should be consciously trusted to choose the language that they want. I have my iOS language (and thus my Safari language) set to German, and it is basically impossible to view the normal version of the English language Wikitravel from my iPhone.
There are no interlanguage links from a given destination page to the corresponding page in another language version.
There are no links anywhere for pages in the sidebar like the Travellers' pub, Help page, or Recent changes.
Recent changes and some other Special pages don't display properly.
Clicking on an edit link on the normal site returns you to the mobile site, making editing almost impossible from a mobile device.
When it happens
What should happen
The "View Normal Wikitravel" button should take you to the normal page in the same language version you are currently viewing.
Interlanguage links should appear at the bottom and lead to the corresponding page in the respective language version.
Sidebar links should be provided somewhere, at the bottom perhaps.
Clicking on Recent changes and other Special pages should either lead to a legible mobile version of the page, or should lead directly to the normal non-mobile page
Once the normal site has been selected, you should not be returned to the mobile site, and editing should be possible as normal.