The policy allowing a visa for passengers arriving in Russian ports on cruise ships( all other ship type passengers did not qualify) to come ashore if accompanied by a registered tour guide holding a blanket group visitor has been in effect for about 60 years. Hotel and other land based tour interests have never liked the fact that thousands of visitors come to St Petersburg each season and don't live off the local economy, eating and sleeping on board ship. Recent reaction to US policies regarding treatment of Russian visa applicants have upset some factions of the electorate and it is widely known that American visitors normally come on cruise ships instead of land and air based tours . These has resulted in the passage of tthe first reading of the proposed bill to require cruise ship passengers to abide by the normal visa rules by a wide margin. There will 2 additonal "readings" before sent to Putin for signature. A lot can happen in the mean time and the Duma is notorious for acting very slowly. It took 8 years to pass a land ownership bill formalizing procedures that had already been adopted and used universally unofficially for 10 years;>)
Since St Petersburg is the crown jewel of Baltic cruises and getting a visa is not a big deal, if the bill ever becomes law, it should not cause major problems despite what major hotels wish. As with everything in Russia there are more than one way to get something done so expect an agreement that still allows business as usual or a modified visa application process.
Additonally, reading the St Petersburg Times is a sure way to get a bad impression of Russia and St Petersburg. The editor, a New Zealander, hates Russia and it is well known policy to print only negative toned articles. We often wonder why he accepted the job when still in N.Z, if he disliked it so much. It is better to get to know the city and country for yourself or ask people with less of an agenda to promote for a more balanced view.
So, do not worry about the proposed law interfering with your visit, it is not going to happen.
Have a great visit
Stan