Well, that's very exciting! It's still smashing a teacup with a sledgehammer, but it does appear to be a more functional sledgehammer. Particularly encouraging were the rates of sustained complete recanalization - which were 36% at 24 hours for alteplase and 58% for tenecteplase - and the rates of intracranial hemorrhage - which were 20% for alteplase and 6% for tenecteplase.
However, the enthusiasm promoted by NEJM, and likely the rest of the internet, should be tempered by the fact that there were only 25 patients in each arm, and there is enough clinical variability between groups that it is not yet practice changing. This was a phase 2B trial, and it is certainly reasonable evidence to proceed with a phase III trial.
Unfortunately, in a replay of prior literature, the authors are all affiliated with Boehringer Ingelheim, the manufacturer of tenecteplase.
"A Randomized Trial of Tenecteplase versus Alteplase for Acute Ischemic Stroke"
Addendum: As Andy Neil appropriately points out, tenecteplase has been studied before - 112 patients over several years, terminated early due to slow enrollment - without seeing a significant advantage.