Its not possible is not true. Iframe can work as we use this for all our Trial download forms. Check out our site for an example of iframe live:
http://www.acronis.com/enterprise/download/backup-recovery/advanced-server-windows/You simple place your Marketo form on to a plain Marketo Landing Page and get you web team to point to that Marketo Landing Page on one of there webpages. Then you (the Marketer) can take that LP and build a program around it for maintance management and reporting. No-longer needing the Web Team constant involvment when building landing pages.
What there are asking defeats the power of Marketo. By limiting the relience of a IT/Web team Marketers can do this themselfs. Yes you can do this through SOAP API, HTTP POST and advanced Munchkin code but may well loose some functionallity.