For those who fear of losing their beloved GPS apps (garmin etc) if they gonna switch to N900, Sygic already announced that they will provide it for Maemo 5.
Sygic announces the compatibility of its Mobile Maps turn-by-turn navigation application with the new Nokia Maemo mobile phones. The application will get ready for sale from Sygic web site e-shop by the end of 2009.

Turn-by-turn voice guided navigation software Sygic Mobile Maps converts mobile phones into full-featured navigation devices. Sygic now extends its current compatibility range to support the new Nokia Maemo 5 OS devices. Further operating systems supported already are iPhone, Symbian, Android and Windows Mobile, incl. Windows Mobile 6.5.
All currently available regional apps for other operating systems are in progress to be available on Nokia Maemo:
Australia & New Zealand, South East Asia (incl. Thailand, Singapore, Malaysia and Indonesia)
Brazil, Colombia, North America (incl. USA, Canada & Mexico), US
Complete Europe, UK & Ireland, Russia
Gulf Countries (Bahrain, Kuwait, Oman, Qatar, Saudi Arabia and United Arab Emirates)
"We are happy to announce the compatibility of Sygic Mobile Maps with Nokia's new Maemo 5 OS. Currently we are in the phase of quality assurance performing final tests. We are working hard to launch it for sales by the end of 2009, but we won't hesitate to make this sooner anytime when ready." comments Anna Hurbanic, Sygic's PR Manager.