Ukrainian defenders have evacuated their last major positions in Lysychansk, ceding pretty much all of Luhansk Oblast to Russian aggressors.
Going into the war, Putin had the stated aim of securing the independence of Donetsk and Luhansk from Ukraine; with today's development, he is substantially closer to being able to announce that Russia has accomplished this. Whatever its tangible impact on the situation on the ground, it is nonetheless a huge symbolic victory for the Kremlin.
It's of some consolation that, from the start of its Donbass Offensive around mid-April, Russia took about 2 and a half months to get to this day. Their gains have been slow and it has always meant giving up men and resources in exchange. However, the Russian army has successfully defied countless predictions of imminent collapse. There's no telling what straw will be the one to break the camel's back, or if that day will indeed come before Kyiv is made to capitulate.