But whats the current stance by the majority of historians on that matter?

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Essentially, the current stance is that responsibility for the outbreak of the war lies with Austria-Hungary, Germany and to an extent, Russia. Austro-Hungarian leaders, namely foreign minister Berchtold and Army Chief of Staff Conrad von Hotzendorff had decided since 1913 that the Dual Monarchy should go to war and crush Serbia at the next best opportunity. That opportunity presented itself with the Assassination of the Archduke, and up until the issuing of the ultimatum they remained pretty hellbent on achieving their goals. When the Serbs essentially accepted the ultimatum with a few qualifications, the Austro-Hungarian response was to shell Belgrade.

That being said, it's doubtful that leader in Vienna would have been as emboldened as they were without expressions of support from German leadership, esp. the Kaiser, in 1908, 1912 and 1913, with the Kaiser even urging the Austro-Hungarian Emperor on two different occasions to go to war in 1913. Without the Blank check in 1914, it's hard again to see Austro-Hungarian leadership pursuing such a disastrous course as single mindedly as they did without the assurance that Germany would back them up.

Finally, while Russia's decision to mobilize it's frontier districts in late July certainly didn't help, mobilization, semi-mobilization and the threat of mobilization were hardly new, having featured in the Moroccan Crises, the Bosnia Crisis, and the Scutari Crisis during the First Balkan War. It's also hard to see what else could have been done to effectively deter the Austro-Hungarians. But finally, the Germans seized the opportunity of Russian mobilization to issue ultimatums and declare war on Russia and France, thus escalating and expanding the conflict. It was this that led to the Invasion of Belgium and the entry of Britain into the war.

In short, Germany was not "unilaterally guilty" of starting the war, though despite popular misconceptions this charge was never made by the Versailles Treaty. However, Germany did play a crucial role in the outbreak of war, without which it is doubtful the war would have happened.