As it seems that the jump from a battleship to a dreadnaught and up is quite high how about another ship to go inbetween the battleships and dreads aka the battlenaught. This gives players another ship to fly and also it can act as a progressive ship towards capitals.
This ship would not be a captial but still have a decent amount of structure/armour/shield can fly in high-sec and use warpgates but not the activation gates in missions to prevent people from farming/tanking/killing everything in them much like captials in lowsec for lvl 5's.
Downside to these ships is they are heavy so can't turn very well but can pack a decent punch (a little better then a battleship but less then a dreads capabilitys) so a good slot layout could be used (much like the maruders atm) say :
8 high slots - 5 gun/missile points
5-7 medium slots (racial dependant for shiled/armour tank etc)
4-6 low slots (racial dependant for shield armour tank etc)
Bonus's could go along the lines of the maruders and other battleships:
75% extra damage dealt by guns/missiles (no 100% to prevent super killing ships with the effectiveness of 10 weapons)
1.5% extra shield or armour rep per level (to prevent super tanked ships in highsec with high struct/armour/shield at get go)
2% resists per level (racial dependant - ammar/caldari?)
-50% cargo bay (to prevent players being able to ferry round items in an ungankable'ish ship) (probably have 150-300m3 space without cargo mods)
This would give a ship that can take a pounding and put out some dps but still be able to use it in high-sec (although maybe only in 0.6 and below to prevent high cluster of big ships in main trading hubs etc)
Just an idea no need to implement it.....