I wouldn't say the best.....and even if they were it took them too long to catch up with sony. halo 3 took almost 3 years into xbox 360's life to make and looks no ware near like halo 4, which was almost 7 years later in the console's life span.
under the best circumstances for them the fastest projects that could be finished would be sports titles.....assuming that the dev kits will arrive sooner.
In sony's case, they do a have a stronger first party line up. they even got uncharted to be a launch title for the vita. this is why i say they can do it more so than Microsoft.
Historically MS' tools are considered the best, at launch of 360/PS3 it was by a fairly large margin, Sony have closed the gap somewhat over the last 7 years, and I know some people who prefer Sony's tools if only because the PS3 linker is a bit faster than the MS one.
As to launch games, it depends if you think the first party titles are what matters, both will have similar support from 3rd parties if they are shipping in similar timeframes. Sony or Ms could ship with no 1st party support and sell out the first Xmas.
The software really won't matter for the first Xmas anyway as long as it's a step above 360/PS3/WiiU, WiiU will likely outsell both combined in their first Xmas just because of supply limitations. Where the software really matters is differentiating for the second Xmas where supply is less of an issue.