US Navy Aviation - Vision 2030 -2035
What will replace the F-18 Super Hornet?
Currently the US Navy intends to replace the F/A-18E/F Super Hornet with a new fighter being developed as part of the US Navy’s Next Generation Air Dominance (NGAD) program. Please note that despite sharing the same name, this program is almost completely unrelated to the US Air Force’s Next Generation Air Dominance program (which is seeking a replacement for the F-22); all further mentions of NGAD in this answer refers to the Navy program unless specified.
Currently the majority of the USN fighter fleet is comprised of Super Hornets. F-35Cs will indirectly replace some of these, as the F-35C was meant to replace the F/A-18C/D fleet (and due to F-35 delays those legacy Hornets had to be replaced by Super Hornets), but concerns about the F-35C’s suitability and cost has lead to the USN reducing the intended size of F-35C squadrons in carrier air wings, meaning the decks will still be mostly covered by Super Hornets.
By around the mid-2030s the US Navy then intends to declare operational capability of their NGAD fighter. NGAD will gradually replace the Super Hornet fleet, serving alongside F-35Cs.
The EA-18G Growler fleet is also targeted for replacement via NGAD, but this is expected to occur later with a different variant or airframe.
It needs to be noted that NGAD is a program that is expected to field multiple airframes, with an expectation that unmanned aircraft (whether they’re separate dedicated designs or just a common, optionally-manned NGAD design) will comprise a sizeable chunk of NGAD airframes. One suggested / example number used by Navy officials was having 40% of NGAD airframes be unmanned soon after entering service, and then increasing that to something like 60% being unmanned later down the line.
As far as what these jets might look like, we can expect at least one manned NGAD design to be a low observable design, likely with two adaptive-cycle engines and a relatively large size that enables it to have a combat radius of 1000 nautical miles or more and carry relatively large munitions internally. As previously mentioned, unmanned NGAD airframes may be identical but with no one in the cockpit, or they could be dedicated designs perhaps resembling the X-47B or something along those lines.
The Navy has also pondered if it should pursue a cheap and affordable bomb truck for counter insurgency, etc work, but it’s unclear if that will result in yet another airframe, or if they’ll just seek to make unmanned platforms like an armed variant of the MQ-25 Stingray (the Navy’s in-development unmanned tanker UAV).
NAVAIR has released new concept art of the F/A-XX, showing canards, a pseudo lambda/delta wing, and, I think, YF-23-style ruddervators (but they might be stabilizers.) The description also calls for more speed and range than F/A-18E/F Block III.