Please read my last post, its been edited lockedbob.
Whilst Emissary's first point is spot on, that goes for any champion and points out the obvious. If you didnt think it was obvious, then you have alot more problems then you realise
The 2nd point i dont agree with, Dr Mundos cleave whilst it will slow, and even with force of nature and ultimate active, your only going to be moving slightly faster then Katarina, the high HP is a concern for any carry champion even if they are relatively well farmed. However, trying to get off that cleave for a slow every 4seconds is hard, and you wont likely kill her in a lane without assistance.
In response to vincent, im fairly certain that dodge runes, masteries. ninja tabi etc all have deminishing returns concerning dodge. So your not going to get 100% dodge on katarina. And thats based off a suspicion of mine and also that based on supposed testing of several other people scattered around this forum.