While it'll take a little time to get used to the new layout and categorization of topics, there may be an issue with players not being able to find their old threads, some of which have been moved with the forum revamp. CCP Wrangler addressed the potential confusion this might cause, and had this to say: "If you had a thread that has disappeared due to these changes, for example if the forum no longer exists, please contact us by creating a petition in the Other Issues - Forums category. Please include a direct link to the thread in question if you have one, otherwise you have to include as much information about the thread as possible to help us find it. The name of the forum, the name of the thread and anything else you can remember would be very helpful."
Although the changes were outlined very clearly in the dev blog 'Forums Refined', it's worth noting the addition of the new "Warfare & Tactics" section, which is 'the home for PvP in EVE: Factional Warfare, 0.0 campaigns, low sec skirmishes and Empire wars'.