Ship skills are the basis of everything about EVE. So I'm going to suggest some changes that actually make more sense than racial destroyers (but I agree with racial battlecruisers).
Tech 1 Ship Skills
Tech 1 ships (and Pirate/Navy ships) require the appropriate Tier 1 skill (frigate/destroyer/cruiser/battlecruiser/battleship) and a matching skill in Spaceship Command, but not the class below it. A new player in EVE always gets basic Spaceship Command and racial Frigate skills. Currently that player has to grind up through both to get to the next tier, and so forth. My suggestion is to streamline this path and allow a player to drop in at whatever size ship they want.
To train for a frigate, you much have Spaceship Command 1
To train for a destroyer, you must have Spaceship Command 2 (not Frigate 4)
To train for a cruiser, you must have Spaceship Command 3 (not Destroyer 4 or Frigate 4)
To train for a battlecruiser, you must have Spaceship Command 4
To train for a battleship, you must have Spaceship Command 5
If a player wants to leap straight into battlecruisers, why force them to train ship skills that are not relevant to the battlecruiser class at all? Spaceship Command 4 then any racial Battlecruiser is open to you to train.
Tech 2 Ship Skills
For Tech 2 ships, change the skill tree to require Advanced Spaceship Command (the cost of this skill should come down to around 10 million +/-) with a corresponding change to the pre-requisite of Spaceship Command 4 (instead of 5). The Advanced Spaceship Command skill level would have to increase with the ship size, just like the Tech 1 version:Tech 2 Frigates require Advanced Spaceship Command 1
Tech 2 Destroyers require Advanced Spaceship Command 2
Tech 2 Cruisers require Advanced Spaceship Command 3
Tech 2 Battlecruisers require Advanced Spaceship Command 4
Tech 2 Battleships require Advanced Spaceship Command 5
In addition you would only need the minimum skills to fly the Tech 1 version of the ship. Using a frigate as the example, Tech 2 Frigates require Advanced Spaceship Command 1and the racial Frigate skill to fly the Tech 1 variant of that frigate. Then for the ship bonuses, map the bonuses based on the source ship type. So (for example) the Enyo is based on the Incursus, which requires Gallente Frigate 3. So to sit in an Enyo, you would train the following skills:
Spaceship Command 4
Gallente Frigate 3
Advanced Spaceship Command 1
Assault Ships 1
A skill tree that makes sense, and can be applied across the board at all levels, and makes it more interesting, since under-training (for newer players) would get them into shiny ships faster, but still leave lots of room to improve how those ships behave. In addition, the ships themselves have the bonuses built to support this model. Keeping with our example of the Enyo, the ship has the following bonuses:
Gallente Frigate Skill Bonus:
5% bonus to Small Hybrid Turret Damage per level
Assault Ships Skill Bonus:
10% bonus to Small Hybrid Turret Optimal Range per level
7.5% bonus to Small Hybrid Turret Tracking Speed per level
These bonuses would unlock improvements in the ship as the pilot continued to train the related skills, but you wouldn't need Gallente Frigate 5 to get into the Enyo.
One of the best things about this change is that it could be announced in advance (far enough in advance) so that players could train the single skill (Advanced Spaceship Command) to the appropriate levels long before the launch of Inferno. In addition, a skill that currently has very little actual value until Capital training, suddenly has value for all classes of players and ship sizes.