Alright guys, I was meant to post this last week when fight was announced and every1 was booking up, however it took me a while to get authorised on livefight.
I have booked flights with Ryanair from London Stensted to Bremen, all in inc admin fees etc £40
There is then a bus you can get straight from Bremen to Hmburg Centre on http://www.bus2fly.de/en/
However to be honest I think i will just get the tram from Bremen airport to Bremen centre (Tram Line 6)
and then get a train from Bremen to Hamburg.
There are two trains every hour to Hamburg. Train tickets can be quite expensive and the cheapest way to travel is to share a group ticket with other people. There is a special ticket called the "Niedersachsen Ticket"
which offers unlimited travel by regional trains inside Lower Saxony area, up to Bremen and Hamburg in one day. This ticket is not valid in high speed trains (D, EC, IC, ICE) so make sure you board the right trains (RE, RB, S-Bahn, Metronom)
when using this ticket. It is valid from 9am to 3am the following day during weekdays and the whole day on weekends. There are two types of tickets, the group ticket (up to 5 people, €28) and the single ticket (€20). These tickets are also valid inside public transport network in some of the cities (Hanover, Hamburg, Bremen and Brunswick)
Hope this helps anyone who hasnt yet booked up or worried about travel around Germany