Thing is, if you look at the Skyline wikipedia, the first Skylines were not launched as GTR's, they were seen more as a luxury sedan. The first GTR was launched in 1969 and then they stopped again in 1973..
Seems nissan wanted to split up the GTR and Skyline badges, having the GTR as the no-nonsense supercar, and the Skyline as a luxury car with a decent enough engine
Of the top of me head, it will sell everywhere as a Nissan.
And as for the Skyline name, the new G35 thing the G37 is being sold in Japan as a Skyline, and G35's over here are sold as Skyline 350GT's
Edit: from wiki: The 11th generation (V35) Nissan Skyline, introduced in June 2001, was based on Nissan's FM platform, shared with the 350Z. The Nissan Skyline used a front-midship engine (VQ35DE), rear-wheel drive layout (all-wheel drive was available for the sedan) to achieve a 52%/48% weight distribution. The V35 was the first Skyline made for export to the United States. There it was sold under the company's luxury brand, Infiniti, as the Infiniti G35.
I just finally decided to give the new AI a run, and I must say, WOW, they are so much faster, I couldn't keep up with them on some combos. Excellent work Scawen