On the Pc gamer podcast, they said, "We are trying to implement custom ship design for the release." That means they may give it to us in a patch
What? They said that there?!
Are you sure that wasn't another game... ./digs up the darned podcast....
BTW, the devs have clearly stated in the past that in-game ship design wouldn't occur (for release! All bets are off now because we can play with expansions and sequels

) because of the constraints of playing in real-time.
That said, we need to clarify what we mean by "ship design" and what we would -- or wouldn't -- want in it.
Things that
would not work: GalCiv II style graphics designing. A) this would obviously take too much time to do in game, and

an out of game editor wouldn't work because in an RTS situation we need to recognize ships "at a glance", not spend time figuring out what it is.
I can't think of anything else to add to this, but I'm sure someone (else) will

Things that could work: Slot based design. When you research a "hull" type, instead of getting it complete with weapons, amour, and shields, instead you get to install those yourself into various "slots". You'd be limited by slot size, maximum tonnage, and whatever equipment you have produced. You'll be able to change weapon type (laser, autocannon, beam), and tonnage (10KT, 20KT), which implies weapon damage (30 DPS, 40DPS), but
not weapon "size" (e. g. a garda flak frigate will
always do anti-very light damage). Same applies for shields and armor -- you can change how much armor, but not what "type" (light, capitol, etc) the unit has. This preserves the ability to identify "at a glance" a given unit type. You can then assign a class name
but not designation to the unit. E. G. instead of Cobalt light frigate I'd have Solar Bean Light Frigates which shoot high-level beam cannons at the enemy.
Such slot based design could take -- literally -- mere seconds as you just grab and shove appropriate components in.
Things that would need hashing out include firing arcs -- can I change / control the firing arcs? -- unit behavior -- can the unit deal with having its weapons shifted around? -- and the oh-so-obvious "will this fit in an expansion, or must we relegate it to a sequel"? Another thing to consider is possible "performance" "issues" -- maybe make higher tonnage ships move slower, and you have to research / place higher level engines to get them to move faster. You could also place power supplies in there too -- they produce / store antimatter at a rate determined by weapons / shields / engine drain (more powerful a generator, faster the antimatter rate, more powerful the equipment, the more power it drains and the less antimatter you get).
Personally, I
hope they add it to an expansion, I'd clamor for it for a sequel, and I'll be disappointed if something of the sort doesn't make it in.