The Ti versions for Nvidia's mid-high and high-end GPUs usually arrive around 9 to 12 months after the launch of the original wave, but this time around, it seems like Nvidia is ready to launch the Ti version of the high-end card together with the regular versions. While the RTX 2080 is rumored to cost US$699 initially, the GTX 2080 Ti could get a US$1,000+ MSRP.
https://www.notebookcheck.net/Nvidia-RTX-2080-Ti-GPU-launching-together-with-RTX-2070-2080.323460.0.html
With the 10-series GPUs, Nvidia achieved a fairly good Desktop/Laptop parity. Sadly, with the new generation it seems the divide will be wide again. There's little chance to see laptops with a 285W TDP card on them, except the largest 17+ inches (MSI Titan and the like).