Reason I'd want to see the Roach: I like the fan art a lot of people are posting, and am particularly fond of some of the fan-made designs (esp. when done correctly... no Arrow IV systems on a 20 ton mech, for example!). While I agree that they have hundreds (more like millions) of mechs to choose from, I'd still like to see some sort of contest or something in which some of the better fan-made designs are included into MWO... I'll probably even suggest that to the devs at some point. Fan-made designs are, after all, how mechs like your re-arted Valkyrie got started.
On a different note, I DO like your re-arted Val... very nice re-rendering of a classic design. I hope it makes it into the game.
Actually, it's not fan-made. That's straight from a Battletech TRO- nearly all the "Unseens" ended up with changed artwork in later books. Fanwank to me in a game like MWO is just that- it's like putting your special snowflake in the middle of a WWII movie. Customizing a canon design? Perfectly normal. Injecting a production model that never existed? Not good. I had no worries with MW4 in that regard because MW4 isn't trying to depict the actual Battletech universe in any canon manner, but MWO is.